diff --git a/app/agent/middleware/activity_log.py b/app/agent/middleware/activity_log.py
index 01ce6c25..51d2b025 100644
--- a/app/agent/middleware/activity_log.py
+++ b/app/agent/middleware/activity_log.py
@@ -6,6 +6,7 @@
 并在每次 Agent 启动时注入轻量索引，完整日志由工具按需查询。
 """
 
+import asyncio
 import json
 import os
 import re
@@ -88,10 +89,6 @@ ACTIVITY_ENTRY_PATTERN = re.compile(r"^-\s+\*\*(?P<time>\d{2}:\d{2})\*\*\s+(?P<s
 class QueryActivityLogInput(BaseModel):
     """查询活动日志工具的输入参数模型。"""
 
-    explanation: Optional[str] = Field(
-        None,
-        description="Clear explanation of why this tool is being used in the current context",
-    )
     keyword: Optional[str] = Field(
         None,
         description=(
@@ -288,17 +285,15 @@ class _ActivityLogToolProvider:
         date: Optional[str] = None,
         days: Optional[int] = DEFAULT_QUERY_DAYS,
         limit: Optional[int] = DEFAULT_QUERY_LIMIT,
-        explanation: Optional[str] = None,
     ) -> str:
         """查询活动日志并返回 JSON 字符串。"""
         logger.info(
-            "查询活动日志: keyword=%s, use_regex=%s, date=%s, days=%s, limit=%s, explanation=%s",
+            "查询活动日志: keyword=%s, use_regex=%s, date=%s, days=%s, limit=%s",
             keyword,
             use_regex,
             date,
             days,
             limit,
-            explanation or "-",
         )
         try:
             payload = query_activity_logs(
@@ -505,6 +500,7 @@ class ActivityLogMiddleware(AgentMiddleware[ActivityLogState, ContextT, Response
         self.retention_days = retention_days
         self.prompt_load_days = prompt_load_days
         self.stream_handler = stream_handler
+        self._background_tasks: set[asyncio.Task[None]] = set()
         self._tool_provider = _ActivityLogToolProvider(activity_dir=activity_dir)
         self.tools = [
             StructuredTool.from_function(
@@ -631,6 +627,44 @@ class ActivityLogMiddleware(AgentMiddleware[ActivityLogState, ContextT, Response
         except Exception as e:
             logger.warning(f"Failed to cleanup old activity logs: {e}")
 
+    def _schedule_activity_recording(self, messages: list) -> None:
+        """提交后台活动记录任务，不阻塞当前 Agent 会话结束。"""
+        task = asyncio.create_task(self._record_activity(messages))
+        self._background_tasks.add(task)
+        task.add_done_callback(self._on_activity_recording_done)
+
+    def _on_activity_recording_done(self, task: asyncio.Task[None]) -> None:
+        """清理已完成的后台任务并记录未捕获异常。"""
+        self._background_tasks.discard(task)
+        try:
+            task.result()
+        except asyncio.CancelledError:
+            logger.debug("活动日志后台记录任务已取消")
+        except Exception as err:
+            logger.warning(f"活动日志后台记录任务失败: {err}")
+
+    async def _record_activity(self, messages: list) -> None:
+        """在后台生成本轮活动摘要并写入活动日志。"""
+        try:
+            # 提取本轮交互
+            round_messages = _extract_last_round(messages)
+            if not round_messages:
+                return
+            if _should_skip_activity_summary(round_messages):
+                return
+
+            # 格式化对话文本
+            conversation_text = _format_conversation_for_summary(round_messages)
+            if not conversation_text:
+                return
+
+            # 调用 LLM 生成摘要
+            summary = await _summarize_with_llm(conversation_text)
+            if summary:
+                await self._append_activity(summary)
+        except Exception as e:
+            logger.warning(f"Failed to record activity: {e}")
+
     async def abefore_agent(
         self, state: ActivityLogState, runtime: Runtime
     ) -> Optional[ActivityLogStateUpdate]:
@@ -699,28 +733,12 @@ class ActivityLogMiddleware(AgentMiddleware[ActivityLogState, ContextT, Response
     async def aafter_agent(
         self, state: ActivityLogState, runtime: Runtime
     ) -> Optional[dict[str, Any]]:
-        """Agent 执行完毕后，调用 LLM 对本轮对话生成摘要并追加到当日活动日志。"""
+        """Agent 执行完毕后，异步提交活动日志记录任务。"""
         try:
             messages = state.get("messages", [])
             if not messages:
                 return None
-
-            # 提取本轮交互
-            round_messages = _extract_last_round(messages)
-            if not round_messages:
-                return None
-            if _should_skip_activity_summary(round_messages):
-                return None
-
-            # 格式化对话文本
-            conversation_text = _format_conversation_for_summary(round_messages)
-            if not conversation_text:
-                return None
-
-            # 调用 LLM 生成摘要
-            summary = await _summarize_with_llm(conversation_text)
-            if summary:
-                await self._append_activity(summary)
+            self._schedule_activity_recording(list(messages))
         except Exception as e:
             logger.warning(f"Failed to record activity: {e}")
 
diff --git a/app/agent/middleware/skills.py b/app/agent/middleware/skills.py
index 15ec7e72..c948b066 100644
--- a/app/agent/middleware/skills.py
+++ b/app/agent/middleware/skills.py
@@ -92,10 +92,6 @@ class SkillsStateUpdate(TypedDict):
 class SkillToolInput(BaseModel):
     """Skill 加载工具的输入参数模型。"""
 
-    explanation: Optional[str] = Field(
-        None,
-        description="Clear explanation of why this skill is needed in the current context",
-    )
     name: str = Field(
         ...,
         description="Skill name or id from the available skills list.",
@@ -460,9 +456,9 @@ class _SkillToolProvider:
             raw_content = await handle.read(MAX_SKILL_FILE_SIZE)
         return raw_content.decode("utf-8", errors="replace"), truncated
 
-    async def load_skill(self, name: str, explanation: Optional[str] = None) -> str:
+    async def load_skill(self, name: str) -> str:
         """加载指定 Skill 的完整说明并返回 JSON 字符串。"""
-        logger.info(f"加载 Skill: name={name}, explanation={explanation or '-'}")
+        logger.info(f"加载 Skill: name={name}")
         try:
             skill = await self._find_skill(name)
             if not skill:
@@ -674,8 +670,7 @@ class SkillsMiddleware(AgentMiddleware[SkillsState, ContextT, ResponseT]):  # no
         if not isinstance(tool_args, dict):
             tool_args = {}
         logger.info(
-            f"开始执行 Skill 工具: name={tool_args.get('name') or '-'}, "
-            f"explanation={tool_args.get('explanation') or '-'}"
+            f"开始执行 Skill 工具: name={tool_args.get('name') or '-'}"
         )
         if self.stream_handler and getattr(self.stream_handler, "is_streaming", False):
             self.stream_handler.record_tool_call(
diff --git a/app/agent/tools/base.py b/app/agent/tools/base.py
index 9f715698..d73a0067 100644
--- a/app/agent/tools/base.py
+++ b/app/agent/tools/base.py
@@ -238,10 +238,6 @@ class MoviePilotTool(BaseTool, metaclass=ABCMeta):
 
         # 获取工具执行提示消息
         tool_message = self.get_tool_message(**kwargs)
-        if not tool_message:
-            explanation = kwargs.get("explanation")
-            if explanation:
-                tool_message = explanation
 
         # 发送工具执行过程消息（流式传输且非最后终结工具时）
         if self._stream_handler and self._stream_handler.is_streaming and not self.return_direct:
@@ -325,16 +321,13 @@ class MoviePilotTool(BaseTool, metaclass=ABCMeta):
         获取工具执行时的友好提示消息。
 
         子类可以重写此方法，根据实际参数生成个性化的提示消息。
-        如果返回 None 或空字符串，将回退使用 explanation 参数。
-
         Args:
-            **kwargs: 工具的所有参数（包括 explanation）
+            **kwargs: 工具的所有参数
 
         Returns:
-            str: 友好的提示消息，如果返回 None 或空字符串则使用 explanation
+            str: 友好的提示消息
         """
-        explanation = kwargs.get("explanation")
-        return str(explanation) if explanation else None
+        return None
 
     @abstractmethod
     async def run(self, **kwargs) -> str:
diff --git a/app/agent/tools/impl/add_custom_filter_rule.py b/app/agent/tools/impl/add_custom_filter_rule.py
index d53ff585..bb7e32c5 100644
--- a/app/agent/tools/impl/add_custom_filter_rule.py
+++ b/app/agent/tools/impl/add_custom_filter_rule.py
@@ -20,8 +20,6 @@ from app.schemas.types import SystemConfigKey
 class AddCustomFilterRuleInput(BaseModel):
     """新增自定义过滤规则工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     rule_id: str = Field(
         ...,
         description="Unique custom rule ID. Only letters and numbers are allowed.",
diff --git a/app/agent/tools/impl/add_download_tasks.py b/app/agent/tools/impl/add_download_tasks.py
index 8fce4a23..5bc909f1 100644
--- a/app/agent/tools/impl/add_download_tasks.py
+++ b/app/agent/tools/impl/add_download_tasks.py
@@ -24,7 +24,6 @@ from app.utils.crypto import HashUtils
 class AddDownloadTasksInput(BaseModel):
     """添加下载任务工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None, description="Clear explanation of why this tool is being used in the current context")
     torrent_url: List[str] = Field(
         ...,
         description="One or more torrent_url values. Supports refs from get_search_results (`hash:id`) and magnet links."
diff --git a/app/agent/tools/impl/add_rule_group.py b/app/agent/tools/impl/add_rule_group.py
index 9f4a8232..82c6b8e2 100644
--- a/app/agent/tools/impl/add_rule_group.py
+++ b/app/agent/tools/impl/add_rule_group.py
@@ -24,8 +24,6 @@ from app.schemas.types import SystemConfigKey
 class AddRuleGroupInput(BaseModel):
     """新增过滤规则组工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     name: str = Field(..., description="New rule group name.")
     rule_string: str = Field(
         ...,
diff --git a/app/agent/tools/impl/add_subscribe.py b/app/agent/tools/impl/add_subscribe.py
index d88f0ae5..9ae2af57 100644
--- a/app/agent/tools/impl/add_subscribe.py
+++ b/app/agent/tools/impl/add_subscribe.py
@@ -15,8 +15,6 @@ from app.schemas.types import MediaType, MessageChannel
 class AddSubscribeInput(BaseModel):
     """添加订阅工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     title: str = Field(
         ...,
         description="The title of the media to subscribe to (e.g., 'The Matrix', 'Breaking Bad')",
diff --git a/app/agent/tools/impl/ask_user_choice.py b/app/agent/tools/impl/ask_user_choice.py
index e6564390..f0a6d023 100644
--- a/app/agent/tools/impl/ask_user_choice.py
+++ b/app/agent/tools/impl/ask_user_choice.py
@@ -24,10 +24,6 @@ class UserChoiceOptionInput(BaseModel):
         ...,
         description="The exact content that will be sent back to the agent after the user clicks this button",
     )
-    description: Optional[str] = Field(
-        None,
-        description="Optional user-facing description stored in chat history after this option is selected",
-    )
 
     @model_validator(mode="after")
     def validate_option(self):
@@ -44,8 +40,6 @@ class UserChoiceOptionInput(BaseModel):
 class AskUserChoiceInput(BaseModel):
     """按钮选择工具输入。"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why the agent needs the user to choose from buttons",)
     message: str = Field(
         ...,
         description="Question or prompt shown to the user together with the buttons",
@@ -166,7 +160,6 @@ class AskUserChoiceTool(MoviePilotTool):
             AgentInteractionOption(
                 label=option.label.strip(),
                 value=option.value.strip(),
-                description=(option.description.strip() if option.description else None),
             )
             for option in options
         ]
@@ -190,7 +183,6 @@ class AskUserChoiceTool(MoviePilotTool):
                     "callback_data": (
                         f"agent_interaction:choice:{request.request_id}:{index}"
                     ),
-                    "description": option.description or option.label,
                 }
             )
             if len(current_row) >= max_per_row:
diff --git a/app/agent/tools/impl/browse_webpage.py b/app/agent/tools/impl/browse_webpage.py
index d576f573..884fbc39 100644
--- a/app/agent/tools/impl/browse_webpage.py
+++ b/app/agent/tools/impl/browse_webpage.py
@@ -47,8 +47,6 @@ class BrowserAction(str, Enum):
 class BrowseWebpageInput(BaseModel):
     """浏览器操作工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this browser action is being performed",)
     action: str = Field(
         ...,
         description=(
diff --git a/app/agent/tools/impl/delete_custom_filter_rule.py b/app/agent/tools/impl/delete_custom_filter_rule.py
index de4969fe..651bb19a 100644
--- a/app/agent/tools/impl/delete_custom_filter_rule.py
+++ b/app/agent/tools/impl/delete_custom_filter_rule.py
@@ -20,8 +20,6 @@ from app.schemas.types import SystemConfigKey
 class DeleteCustomFilterRuleInput(BaseModel):
     """删除自定义过滤规则工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     rule_id: str = Field(..., description="Custom rule ID to delete.")
 
 
diff --git a/app/agent/tools/impl/delete_download_history.py b/app/agent/tools/impl/delete_download_history.py
index 5a3753d0..acb3c427 100644
--- a/app/agent/tools/impl/delete_download_history.py
+++ b/app/agent/tools/impl/delete_download_history.py
@@ -13,8 +13,6 @@ from app.log import logger
 class DeleteDownloadHistoryInput(BaseModel):
     """删除下载历史记录工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     history_id: int = Field(
         ..., description="The ID of the download history record to delete"
     )
diff --git a/app/agent/tools/impl/delete_download_tasks.py b/app/agent/tools/impl/delete_download_tasks.py
index beac5f42..ba17164f 100644
--- a/app/agent/tools/impl/delete_download_tasks.py
+++ b/app/agent/tools/impl/delete_download_tasks.py
@@ -13,8 +13,6 @@ from app.log import logger
 class DeleteDownloadTasksInput(BaseModel):
     """删除下载任务工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     hash: str = Field(
         ..., description="Task hash (can be obtained from query_download_tasks tool)"
     )
diff --git a/app/agent/tools/impl/delete_rule_group.py b/app/agent/tools/impl/delete_rule_group.py
index d7804293..db250aa4 100644
--- a/app/agent/tools/impl/delete_rule_group.py
+++ b/app/agent/tools/impl/delete_rule_group.py
@@ -19,8 +19,6 @@ from app.schemas.types import SystemConfigKey
 class DeleteRuleGroupInput(BaseModel):
     """删除过滤规则组工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     name: str = Field(..., description="Rule group name to delete.")
 
 
diff --git a/app/agent/tools/impl/delete_subscribe.py b/app/agent/tools/impl/delete_subscribe.py
index 9fa2427f..91fb100f 100644
--- a/app/agent/tools/impl/delete_subscribe.py
+++ b/app/agent/tools/impl/delete_subscribe.py
@@ -16,8 +16,6 @@ from app.schemas.types import EventType
 class DeleteSubscribeInput(BaseModel):
     """删除订阅工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     subscribe_id: int = Field(
         ...,
         description="The ID of the subscription to delete (can be obtained from query_subscribes tool)",
diff --git a/app/agent/tools/impl/delete_transfer_history.py b/app/agent/tools/impl/delete_transfer_history.py
index fb90e271..75c3b59a 100644
--- a/app/agent/tools/impl/delete_transfer_history.py
+++ b/app/agent/tools/impl/delete_transfer_history.py
@@ -15,8 +15,6 @@ from app.schemas import FileItem
 class DeleteTransferHistoryInput(BaseModel):
     """删除整理历史记录工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     history_id: int = Field(
         ..., description="The ID of the transfer history record to delete"
     )
diff --git a/app/agent/tools/impl/execute_command.py b/app/agent/tools/impl/execute_command.py
index 18127d1b..91e7230a 100644
--- a/app/agent/tools/impl/execute_command.py
+++ b/app/agent/tools/impl/execute_command.py
@@ -135,7 +135,6 @@ class _CommandOutput:
 class ExecuteCommandInput(BaseModel):
     """执行 Shell 命令工具的输入参数模型。"""
 
-    explanation: Optional[str] = Field(None, description="Clear explanation of why this command action is needed")
     action: Optional[Literal["start", "read", "wait", "write", "kill", "run"]] = Field(
         "start",
         description=(
diff --git a/app/agent/tools/impl/get_recommendations.py b/app/agent/tools/impl/get_recommendations.py
index 88ef6ea3..c6331002 100644
--- a/app/agent/tools/impl/get_recommendations.py
+++ b/app/agent/tools/impl/get_recommendations.py
@@ -15,8 +15,6 @@ from app.schemas.types import MediaType, media_type_to_agent
 class GetRecommendationsInput(BaseModel):
     """获取推荐工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     source: Optional[str] = Field(
         "tmdb_trending",
         description="Recommendation source: "
diff --git a/app/agent/tools/impl/get_search_results.py b/app/agent/tools/impl/get_search_results.py
index f1e8f631..d045346f 100644
--- a/app/agent/tools/impl/get_search_results.py
+++ b/app/agent/tools/impl/get_search_results.py
@@ -21,8 +21,6 @@ from ._torrent_search_utils import (
 class GetSearchResultsInput(BaseModel):
     """获取搜索结果工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     site: Optional[List[str]] = Field(None, description="Site name filters")
     season: Optional[List[str]] = Field(None, description="Season or episode filters")
     free_state: Optional[List[str]] = Field(None, description="Promotion state filters")
diff --git a/app/agent/tools/impl/install_plugin.py b/app/agent/tools/impl/install_plugin.py
index d6cbb705..71ce59cf 100644
--- a/app/agent/tools/impl/install_plugin.py
+++ b/app/agent/tools/impl/install_plugin.py
@@ -19,8 +19,6 @@ from app.log import logger
 class InstallPluginInput(BaseModel):
     """安装插件工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     plugin_id: str = Field(
         ...,
         description="Exact plugin ID to install. Use query_market_plugins first to find the correct plugin_id.",
diff --git a/app/agent/tools/impl/list_directory.py b/app/agent/tools/impl/list_directory.py
index a179be5f..99e3911d 100644
--- a/app/agent/tools/impl/list_directory.py
+++ b/app/agent/tools/impl/list_directory.py
@@ -17,7 +17,6 @@ from app.utils.string import StringUtils
 
 class ListDirectoryInput(BaseModel):
     """查询文件系统目录内容工具的输入参数模型"""
-    explanation: Optional[str] = Field(None, description="Clear explanation of why this tool is being used in the current context")
     path: str = Field(..., description="Directory path to list contents (e.g., '/home/user/downloads' or 'C:/Downloads')")
     storage: Optional[str] = Field("local", description="Storage type (default: 'local' for local file system, can be 'smb', 'alist', etc.)")
     sort_by: Optional[str] = Field("name", description="Sort order: 'name' for alphabetical sorting, 'time' for modification time sorting (default: 'name')")
diff --git a/app/agent/tools/impl/list_slash_commands.py b/app/agent/tools/impl/list_slash_commands.py
index 74d35265..182cc155 100644
--- a/app/agent/tools/impl/list_slash_commands.py
+++ b/app/agent/tools/impl/list_slash_commands.py
@@ -13,8 +13,6 @@ from app.log import logger
 class ListSlashCommandsInput(BaseModel):
     """查询所有可用斜杠命令工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
 
 
 class ListSlashCommandsTool(MoviePilotTool):
diff --git a/app/agent/tools/impl/query_builtin_filter_rules.py b/app/agent/tools/impl/query_builtin_filter_rules.py
index 586a48d4..5a607033 100644
--- a/app/agent/tools/impl/query_builtin_filter_rules.py
+++ b/app/agent/tools/impl/query_builtin_filter_rules.py
@@ -18,8 +18,6 @@ from app.log import logger
 class QueryBuiltinFilterRulesInput(BaseModel):
     """查询内置过滤规则工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     rule_ids: Optional[List[str]] = Field(
         None,
         description="Optional list of built-in rule IDs to query. If omitted, return all built-in rules.",
diff --git a/app/agent/tools/impl/query_custom_filter_rules.py b/app/agent/tools/impl/query_custom_filter_rules.py
index 84dcb2f9..7767373c 100644
--- a/app/agent/tools/impl/query_custom_filter_rules.py
+++ b/app/agent/tools/impl/query_custom_filter_rules.py
@@ -19,8 +19,6 @@ from app.log import logger
 class QueryCustomFilterRulesInput(BaseModel):
     """查询自定义过滤规则工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     rule_ids: Optional[List[str]] = Field(
         None,
         description="Optional list of custom rule IDs to query. If omitted, return all custom rules.",
diff --git a/app/agent/tools/impl/query_custom_identifiers.py b/app/agent/tools/impl/query_custom_identifiers.py
index b6a3bbf0..9b8bc7e0 100644
--- a/app/agent/tools/impl/query_custom_identifiers.py
+++ b/app/agent/tools/impl/query_custom_identifiers.py
@@ -15,8 +15,6 @@ from app.schemas.types import SystemConfigKey
 class QueryCustomIdentifiersInput(BaseModel):
     """查询自定义识别词工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
 
 
 class QueryCustomIdentifiersTool(MoviePilotTool):
diff --git a/app/agent/tools/impl/query_directory_settings.py b/app/agent/tools/impl/query_directory_settings.py
index 71a68ed5..78c34a98 100644
--- a/app/agent/tools/impl/query_directory_settings.py
+++ b/app/agent/tools/impl/query_directory_settings.py
@@ -13,7 +13,6 @@ from app.log import logger
 
 class QueryDirectorySettingsInput(BaseModel):
     """查询系统目录设置工具的输入参数模型"""
-    explanation: Optional[str] = Field(None, description="Clear explanation of why this tool is being used in the current context")
     directory_type: Optional[str] = Field("all",
                                           description="Filter directories by type: 'download' for download directories, 'library' for media library directories, 'all' for all directories")
     storage_type: Optional[str] = Field("all",
diff --git a/app/agent/tools/impl/query_doctor_report.py b/app/agent/tools/impl/query_doctor_report.py
index 46fe0fe4..4e9a4958 100644
--- a/app/agent/tools/impl/query_doctor_report.py
+++ b/app/agent/tools/impl/query_doctor_report.py
@@ -14,10 +14,6 @@ from app.log import logger
 class QueryDoctorReportInput(BaseModel):
     """查询 Doctor 诊断报告工具的输入参数模型。"""
 
-    explanation: Optional[str] = Field(
-        None,
-        description="Clear explanation of why this tool is being used in the current context",
-    )
     deep: Optional[bool] = Field(
         False,
         description=(
diff --git a/app/agent/tools/impl/query_download_tasks.py b/app/agent/tools/impl/query_download_tasks.py
index c3d1230a..523fa071 100644
--- a/app/agent/tools/impl/query_download_tasks.py
+++ b/app/agent/tools/impl/query_download_tasks.py
@@ -16,7 +16,6 @@ from app.schemas.types import TorrentQueryStatus, media_type_to_agent
 
 class QueryDownloadTasksInput(BaseModel):
     """查询下载工具的输入参数模型"""
-    explanation: Optional[str] = Field(None, description="Clear explanation of why this tool is being used in the current context")
     downloader: Optional[str] = Field(None,
                                       description="Name of specific downloader to query (optional, if not provided queries all configured downloaders)")
     status: Optional[str] = Field("all",
diff --git a/app/agent/tools/impl/query_downloaders.py b/app/agent/tools/impl/query_downloaders.py
index a2d51dfd..5c2bfa03 100644
--- a/app/agent/tools/impl/query_downloaders.py
+++ b/app/agent/tools/impl/query_downloaders.py
@@ -14,9 +14,6 @@ from app.schemas.types import SystemConfigKey
 
 class QueryDownloadersInput(BaseModel):
     """查询下载器工具的输入参数模型"""
-    explanation: Optional[str] = Field(None, description="Clear explanation of why this tool is being used in the current context")
-
-
 class QueryDownloadersTool(MoviePilotTool):
     name: str = "query_downloaders"
     tags: list[str] = [
diff --git a/app/agent/tools/impl/query_episode_schedule.py b/app/agent/tools/impl/query_episode_schedule.py
index c237f567..08a9a58e 100644
--- a/app/agent/tools/impl/query_episode_schedule.py
+++ b/app/agent/tools/impl/query_episode_schedule.py
@@ -13,7 +13,6 @@ from app.log import logger
 
 class QueryEpisodeScheduleInput(BaseModel):
     """查询剧集上映时间工具的输入参数模型"""
-    explanation: Optional[str] = Field(None, description="Clear explanation of why this tool is being used in the current context")
     tmdb_id: int = Field(..., description="TMDB ID of the TV series (can be obtained from search_media tool)")
     season: int = Field(..., description="Season number to query")
     episode_group: Optional[str] = Field(None, description="Episode group ID (optional)")
diff --git a/app/agent/tools/impl/query_installed_plugins.py b/app/agent/tools/impl/query_installed_plugins.py
index d9ce510f..99c50304 100644
--- a/app/agent/tools/impl/query_installed_plugins.py
+++ b/app/agent/tools/impl/query_installed_plugins.py
@@ -22,8 +22,6 @@ from app.log import logger
 class QueryInstalledPluginsInput(BaseModel):
     """查询已安装插件工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     query: Optional[str] = Field(
         None,
         description="Optional keyword to filter installed plugins by plugin ID, name, description, or author.",
diff --git a/app/agent/tools/impl/query_library_exists.py b/app/agent/tools/impl/query_library_exists.py
index 3bb2b37c..10aa0436 100644
--- a/app/agent/tools/impl/query_library_exists.py
+++ b/app/agent/tools/impl/query_library_exists.py
@@ -77,7 +77,6 @@ def _build_tv_server_result(existing_seasons: OrderedDict, total_seasons: Ordere
 
 class QueryLibraryExistsInput(BaseModel):
     """查询媒体库工具的输入参数模型"""
-    explanation: Optional[str] = Field(None, description="Clear explanation of why this tool is being used in the current context")
     tmdb_id: Optional[int] = Field(None, description="TMDB ID (can be obtained from search_media tool). Either tmdb_id or douban_id must be provided.")
     douban_id: Optional[str] = Field(None, description="Douban ID (can be obtained from search_media tool). Either tmdb_id or douban_id must be provided.")
     media_type: Optional[str] = Field(None, description="Allowed values: movie, tv")
diff --git a/app/agent/tools/impl/query_library_latest.py b/app/agent/tools/impl/query_library_latest.py
index 6c045a20..5773274c 100644
--- a/app/agent/tools/impl/query_library_latest.py
+++ b/app/agent/tools/impl/query_library_latest.py
@@ -18,8 +18,6 @@ PAGE_SIZE = 20
 class QueryLibraryLatestInput(BaseModel):
     """查询媒体服务器最近入库影片工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     server: Optional[str] = Field(
         None,
         description="Media server name (optional, if not specified queries all enabled media servers)",
diff --git a/app/agent/tools/impl/query_market_plugins.py b/app/agent/tools/impl/query_market_plugins.py
index 37d70849..6330c48f 100644
--- a/app/agent/tools/impl/query_market_plugins.py
+++ b/app/agent/tools/impl/query_market_plugins.py
@@ -21,8 +21,6 @@ from app.log import logger
 class QueryMarketPluginsInput(BaseModel):
     """查询插件市场工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     query: Optional[str] = Field(
         None,
         description="Optional keyword to filter plugin market results by plugin ID, name, description, or author.",
diff --git a/app/agent/tools/impl/query_media_detail.py b/app/agent/tools/impl/query_media_detail.py
index 7d9d50dd..0df00909 100644
--- a/app/agent/tools/impl/query_media_detail.py
+++ b/app/agent/tools/impl/query_media_detail.py
@@ -18,7 +18,6 @@ SEASON_PREVIEW_LIMIT = 100
 
 class QueryMediaDetailInput(BaseModel):
     """查询媒体详情工具的输入参数模型"""
-    explanation: Optional[str] = Field(None, description="Clear explanation of why this tool is being used in the current context")
     tmdb_id: Optional[int] = Field(None, description="TMDB ID of the media (movie or TV series, can be obtained from search_media tool)")
     douban_id: Optional[str] = Field(None, description="Douban ID of the media (alternative to tmdb_id)")
     media_type: str = Field(..., description="Allowed values: movie, tv")
diff --git a/app/agent/tools/impl/query_personas.py b/app/agent/tools/impl/query_personas.py
index 257ecfef..9050a472 100644
--- a/app/agent/tools/impl/query_personas.py
+++ b/app/agent/tools/impl/query_personas.py
@@ -14,8 +14,6 @@ from app.log import logger
 class QueryPersonasInput(BaseModel):
     """查询人格工具的输入参数模型。"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     query: Optional[str] = Field(
         None,
         description=(
diff --git a/app/agent/tools/impl/query_plugin_capabilities.py b/app/agent/tools/impl/query_plugin_capabilities.py
index 1f02ce59..5fe33b5b 100644
--- a/app/agent/tools/impl/query_plugin_capabilities.py
+++ b/app/agent/tools/impl/query_plugin_capabilities.py
@@ -14,8 +14,6 @@ from app.log import logger
 class QueryPluginCapabilitiesInput(BaseModel):
     """查询插件能力工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     plugin_id: Optional[str] = Field(
         None,
         description="Optional plugin ID to query capabilities for a specific plugin. "
diff --git a/app/agent/tools/impl/query_plugin_config.py b/app/agent/tools/impl/query_plugin_config.py
index a3356d00..22fe2baa 100644
--- a/app/agent/tools/impl/query_plugin_config.py
+++ b/app/agent/tools/impl/query_plugin_config.py
@@ -15,8 +15,6 @@ from app.log import logger
 class QueryPluginConfigInput(BaseModel):
     """查询插件配置工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     plugin_id: str = Field(
         ...,
         description="The plugin ID to query. Use query_installed_plugins first to discover valid plugin IDs.",
diff --git a/app/agent/tools/impl/query_plugin_data.py b/app/agent/tools/impl/query_plugin_data.py
index 3eeb48c4..1b7faaed 100644
--- a/app/agent/tools/impl/query_plugin_data.py
+++ b/app/agent/tools/impl/query_plugin_data.py
@@ -19,8 +19,6 @@ from app.log import logger
 class QueryPluginDataInput(BaseModel):
     """查询插件数据工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     plugin_id: str = Field(
         ...,
         description="The plugin ID to query. Use query_installed_plugins first to discover valid plugin IDs.",
diff --git a/app/agent/tools/impl/query_popular_subscribes.py b/app/agent/tools/impl/query_popular_subscribes.py
index be37a707..a3b8685b 100644
--- a/app/agent/tools/impl/query_popular_subscribes.py
+++ b/app/agent/tools/impl/query_popular_subscribes.py
@@ -18,7 +18,6 @@ MAX_PAGE_SIZE = 50
 
 class QueryPopularSubscribesInput(BaseModel):
     """查询热门订阅工具的输入参数模型"""
-    explanation: Optional[str] = Field(None, description="Clear explanation of why this tool is being used in the current context")
     media_type: str = Field(..., description="Allowed values: movie, tv")
     page: Optional[int] = Field(1, description="Page number for pagination (default: 1)")
     count: Optional[int] = Field(30, description="Number of items per page (default: 30, max: 50)")
diff --git a/app/agent/tools/impl/query_rule_groups.py b/app/agent/tools/impl/query_rule_groups.py
index 6badc9bb..61b4cf3d 100644
--- a/app/agent/tools/impl/query_rule_groups.py
+++ b/app/agent/tools/impl/query_rule_groups.py
@@ -19,8 +19,6 @@ from app.log import logger
 class QueryRuleGroupsInput(BaseModel):
     """查询规则组工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     group_names: Optional[List[str]] = Field(
         None,
         description="Optional list of rule group names to query. If omitted, return all rule groups.",
diff --git a/app/agent/tools/impl/query_schedulers.py b/app/agent/tools/impl/query_schedulers.py
index 2a53edc7..b73249a8 100644
--- a/app/agent/tools/impl/query_schedulers.py
+++ b/app/agent/tools/impl/query_schedulers.py
@@ -12,9 +12,6 @@ from app.log import logger
 
 class QuerySchedulersInput(BaseModel):
     """查询定时服务工具的输入参数模型"""
-    explanation: Optional[str] = Field(None, description="Clear explanation of why this tool is being used in the current context")
-
-
 class QuerySchedulersTool(MoviePilotTool):
     name: str = "query_schedulers"
     tags: list[str] = [
diff --git a/app/agent/tools/impl/query_site_userdata.py b/app/agent/tools/impl/query_site_userdata.py
index 29def856..6b2e5c07 100644
--- a/app/agent/tools/impl/query_site_userdata.py
+++ b/app/agent/tools/impl/query_site_userdata.py
@@ -22,8 +22,6 @@ def _preview_list(value, limit: int = SITE_USERDATA_DETAIL_PREVIEW_LIMIT) -> tup
 class QuerySiteUserdataInput(BaseModel):
     """查询站点用户数据工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     site_id: int = Field(
         ...,
         description="The ID of the site to query user data for (can be obtained from query_sites tool)",
diff --git a/app/agent/tools/impl/query_sites.py b/app/agent/tools/impl/query_sites.py
index 4088e932..4ba5686f 100644
--- a/app/agent/tools/impl/query_sites.py
+++ b/app/agent/tools/impl/query_sites.py
@@ -14,8 +14,6 @@ from app.log import logger
 class QuerySitesInput(BaseModel):
     """查询站点工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     status: Optional[str] = Field(
         "all",
         description="Filter sites by status: 'active' for enabled sites, 'inactive' for disabled sites, 'all' for all sites",
diff --git a/app/agent/tools/impl/query_subscribe_history.py b/app/agent/tools/impl/query_subscribe_history.py
index cee03d9c..4bd943be 100644
--- a/app/agent/tools/impl/query_subscribe_history.py
+++ b/app/agent/tools/impl/query_subscribe_history.py
@@ -17,8 +17,6 @@ PAGE_SIZE = 20
 class QuerySubscribeHistoryInput(BaseModel):
     """查询订阅历史工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     media_type: Optional[str] = Field(
         "all", description="Allowed values: movie, tv, all"
     )
diff --git a/app/agent/tools/impl/query_subscribe_shares.py b/app/agent/tools/impl/query_subscribe_shares.py
index 850fdd4b..447621cd 100644
--- a/app/agent/tools/impl/query_subscribe_shares.py
+++ b/app/agent/tools/impl/query_subscribe_shares.py
@@ -15,7 +15,6 @@ MAX_PAGE_SIZE = 50
 
 class QuerySubscribeSharesInput(BaseModel):
     """查询订阅分享工具的输入参数模型"""
-    explanation: Optional[str] = Field(None, description="Clear explanation of why this tool is being used in the current context")
     name: Optional[str] = Field(None, description="Filter shares by media name (partial match, optional)")
     page: Optional[int] = Field(1, description="Page number for pagination (default: 1)")
     count: Optional[int] = Field(30, description="Number of items per page (default: 30, max: 50)")
diff --git a/app/agent/tools/impl/query_subscribes.py b/app/agent/tools/impl/query_subscribes.py
index b5143754..458e114f 100644
--- a/app/agent/tools/impl/query_subscribes.py
+++ b/app/agent/tools/impl/query_subscribes.py
@@ -48,8 +48,6 @@ QUERY_SUBSCRIBE_OUTPUT_FIELDS = [
 class QuerySubscribesInput(BaseModel):
     """查询订阅工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     status: Optional[str] = Field(
         "all",
         description="Filter subscriptions by status: 'R' for enabled subscriptions, 'S' for paused ones, 'all' for all subscriptions",
diff --git a/app/agent/tools/impl/query_system_settings.py b/app/agent/tools/impl/query_system_settings.py
index 5b7417e7..58aa929c 100644
--- a/app/agent/tools/impl/query_system_settings.py
+++ b/app/agent/tools/impl/query_system_settings.py
@@ -23,8 +23,6 @@ from app.log import logger
 class QuerySystemSettingsInput(BaseModel):
     """查询系统设置工具的输入参数模型。"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     setting_key: Optional[str] = Field(
         None,
         description=(
diff --git a/app/agent/tools/impl/query_transfer_history.py b/app/agent/tools/impl/query_transfer_history.py
index 1c3d1461..8b33d2f7 100644
--- a/app/agent/tools/impl/query_transfer_history.py
+++ b/app/agent/tools/impl/query_transfer_history.py
@@ -15,7 +15,6 @@ from app.utils.jieba import cut as jieba_cut
 
 class QueryTransferHistoryInput(BaseModel):
     """查询整理历史记录工具的输入参数模型"""
-    explanation: Optional[str] = Field(None, description="Clear explanation of why this tool is being used in the current context")
     title: Optional[str] = Field(None, description="Search by title (optional, supports partial match)")
     status: Optional[str] = Field("all",
                                   description="Filter by status: 'success' for successful transfers, 'failed' for failed transfers, 'all' for all records (default: 'all')")
diff --git a/app/agent/tools/impl/query_workflows.py b/app/agent/tools/impl/query_workflows.py
index 964a58fb..fce77151 100644
--- a/app/agent/tools/impl/query_workflows.py
+++ b/app/agent/tools/impl/query_workflows.py
@@ -13,7 +13,6 @@ from app.log import logger
 
 class QueryWorkflowsInput(BaseModel):
     """查询工作流工具的输入参数模型"""
-    explanation: Optional[str] = Field(None, description="Clear explanation of why this tool is being used in the current context")
     state: Optional[str] = Field("all", description="Filter workflows by state: 'W' for waiting, 'R' for running, 'P' for paused, 'S' for success, 'F' for failed, 'all' for all workflows (default: 'all')")
     name: Optional[str] = Field(None, description="Filter workflows by name (partial match, optional)")
     trigger_type: Optional[str] = Field("all", description="Filter workflows by trigger type: 'timer' for scheduled, 'event' for event-triggered, 'manual' for manual, 'all' for all types (default: 'all')")
diff --git a/app/agent/tools/impl/recognize_captcha.py b/app/agent/tools/impl/recognize_captcha.py
index f36c57ca..2c9402f4 100644
--- a/app/agent/tools/impl/recognize_captcha.py
+++ b/app/agent/tools/impl/recognize_captcha.py
@@ -15,10 +15,6 @@ from app.log import logger
 class RecognizeCaptchaInput(BaseModel):
     """识别图形验证码工具的输入参数模型。"""
 
-    explanation: Optional[str] = Field(
-        None,
-        description="Clear explanation of why this captcha image needs to be recognized",
-    )
     image_url: str = Field(
         ...,
         description=(
diff --git a/app/agent/tools/impl/recognize_media.py b/app/agent/tools/impl/recognize_media.py
index c4661b8b..ee43684a 100644
--- a/app/agent/tools/impl/recognize_media.py
+++ b/app/agent/tools/impl/recognize_media.py
@@ -16,7 +16,6 @@ from app.schemas.types import media_type_to_agent
 
 class RecognizeMediaInput(BaseModel):
     """识别媒体信息工具的输入参数模型"""
-    explanation: Optional[str] = Field(None, description="Clear explanation of why this tool is being used in the current context")
     title: Optional[str] = Field(None, description="The title of the torrent/media to recognize (required for torrent recognition)")
     subtitle: Optional[str] = Field(None, description="The subtitle or description of the torrent (optional, helps improve recognition accuracy)")
     path: Optional[str] = Field(None, description="The file path to recognize (required for file recognition, mutually exclusive with title)")
diff --git a/app/agent/tools/impl/reload_plugin.py b/app/agent/tools/impl/reload_plugin.py
index 1ff7eb76..82593320 100644
--- a/app/agent/tools/impl/reload_plugin.py
+++ b/app/agent/tools/impl/reload_plugin.py
@@ -17,8 +17,6 @@ from app.log import logger
 class ReloadPluginInput(BaseModel):
     """重载插件工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     plugin_id: str = Field(
         ...,
         description="The plugin ID to reload so the latest saved config takes effect.",
diff --git a/app/agent/tools/impl/run_scheduler.py b/app/agent/tools/impl/run_scheduler.py
index 708c0ae5..040b2431 100644
--- a/app/agent/tools/impl/run_scheduler.py
+++ b/app/agent/tools/impl/run_scheduler.py
@@ -12,8 +12,6 @@ from app.log import logger
 class RunSchedulerInput(BaseModel):
     """运行定时服务工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     job_id: str = Field(
         ...,
         description="The ID of the scheduled job to run (can be obtained from query_schedulers tool)",
diff --git a/app/agent/tools/impl/run_slash_command.py b/app/agent/tools/impl/run_slash_command.py
index d6a8b89f..72bc903c 100644
--- a/app/agent/tools/impl/run_slash_command.py
+++ b/app/agent/tools/impl/run_slash_command.py
@@ -15,8 +15,6 @@ from app.schemas.types import EventType, MessageChannel
 class RunSlashCommandInput(BaseModel):
     """运行斜杠命令工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     command: str = Field(
         ...,
         description="The slash command to execute, e.g. '/cookiecloud'. "
diff --git a/app/agent/tools/impl/run_workflow.py b/app/agent/tools/impl/run_workflow.py
index 21bbc25a..91142c75 100644
--- a/app/agent/tools/impl/run_workflow.py
+++ b/app/agent/tools/impl/run_workflow.py
@@ -14,8 +14,6 @@ from app.log import logger
 class RunWorkflowInput(BaseModel):
     """执行工作流工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     workflow_id: int = Field(
         ..., description="Workflow ID (can be obtained from query_workflows tool)"
     )
diff --git a/app/agent/tools/impl/scrape_metadata.py b/app/agent/tools/impl/scrape_metadata.py
index 26a6cdb8..f23ea8ab 100644
--- a/app/agent/tools/impl/scrape_metadata.py
+++ b/app/agent/tools/impl/scrape_metadata.py
@@ -16,8 +16,6 @@ from app.schemas import FileItem
 class ScrapeMetadataInput(BaseModel):
     """刮削媒体元数据工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     path: str = Field(
         ...,
         description="Path to the file or directory to scrape metadata for (e.g., '/path/to/file.mkv' or '/path/to/directory')",
diff --git a/app/agent/tools/impl/search_media.py b/app/agent/tools/impl/search_media.py
index 8c36a7b5..ca26cfa8 100644
--- a/app/agent/tools/impl/search_media.py
+++ b/app/agent/tools/impl/search_media.py
@@ -14,7 +14,6 @@ from app.schemas.types import MediaType, media_type_to_agent
 
 class SearchMediaInput(BaseModel):
     """搜索媒体工具的输入参数模型"""
-    explanation: Optional[str] = Field(None, description="Clear explanation of why this tool is being used in the current context")
     title: str = Field(..., description="The title of the media to search for (e.g., 'The Matrix', 'Breaking Bad')")
     year: Optional[str] = Field(None, description="Release year of the media (optional, helps narrow down results)")
     media_type: Optional[str] = Field(None,
diff --git a/app/agent/tools/impl/search_person.py b/app/agent/tools/impl/search_person.py
index 73431628..e6a7fa58 100644
--- a/app/agent/tools/impl/search_person.py
+++ b/app/agent/tools/impl/search_person.py
@@ -13,7 +13,6 @@ from app.log import logger
 
 class SearchPersonInput(BaseModel):
     """搜索人物工具的输入参数模型"""
-    explanation: Optional[str] = Field(None, description="Clear explanation of why this tool is being used in the current context")
     name: str = Field(..., description="The name of the person to search for (e.g., 'Tom Hanks', '周杰伦')")
 
 
diff --git a/app/agent/tools/impl/search_person_credits.py b/app/agent/tools/impl/search_person_credits.py
index 806ac203..aed312f2 100644
--- a/app/agent/tools/impl/search_person_credits.py
+++ b/app/agent/tools/impl/search_person_credits.py
@@ -15,7 +15,6 @@ from app.log import logger
 
 class SearchPersonCreditsInput(BaseModel):
     """搜索演员参演作品工具的输入参数模型"""
-    explanation: Optional[str] = Field(None, description="Clear explanation of why this tool is being used in the current context")
     person_id: int = Field(..., description="The ID of the person/actor to search for credits (e.g., 31 for Tom Hanks in TMDB)")
     source: str = Field(..., description="The data source: 'tmdb' for TheMovieDB, 'douban' for Douban, 'bangumi' for Bangumi")
     page: Optional[int] = Field(1, description="Page number for pagination (default: 1)")
diff --git a/app/agent/tools/impl/search_subscribe.py b/app/agent/tools/impl/search_subscribe.py
index f9e0be88..0487ebe0 100644
--- a/app/agent/tools/impl/search_subscribe.py
+++ b/app/agent/tools/impl/search_subscribe.py
@@ -15,7 +15,6 @@ from app.schemas.types import media_type_to_agent
 
 class SearchSubscribeInput(BaseModel):
     """搜索订阅缺失剧集工具的输入参数模型"""
-    explanation: Optional[str] = Field(None, description="Clear explanation of why this tool is being used in the current context")
     subscribe_id: int = Field(..., description="The ID of the subscription to search for missing episodes (can be obtained from query_subscribes tool)")
     manual: Optional[bool] = Field(False, description="Whether this is a manual search (default: False)")
     filter_groups: Optional[List[str]] = Field(None,
diff --git a/app/agent/tools/impl/search_torrents.py b/app/agent/tools/impl/search_torrents.py
index 0e7b3baf..720da1be 100644
--- a/app/agent/tools/impl/search_torrents.py
+++ b/app/agent/tools/impl/search_torrents.py
@@ -20,7 +20,6 @@ from ._torrent_search_utils import (
 
 class SearchTorrentsInput(BaseModel):
     """搜索种子工具的输入参数模型"""
-    explanation: Optional[str] = Field(None, description="Clear explanation of why this tool is being used in the current context")
     tmdb_id: Optional[int] = Field(None, description="TMDB ID (can be obtained from search_media tool). Either tmdb_id or douban_id must be provided.")
     douban_id: Optional[str] = Field(None, description="Douban ID (can be obtained from search_media tool). Either tmdb_id or douban_id must be provided.")
     media_type: Optional[str] = Field(None, description="Allowed values: movie, tv")
diff --git a/app/agent/tools/impl/search_web.py b/app/agent/tools/impl/search_web.py
index ad718af1..52eff860 100644
--- a/app/agent/tools/impl/search_web.py
+++ b/app/agent/tools/impl/search_web.py
@@ -48,10 +48,6 @@ class _SearchSiteFilter:
 class SearchWebInput(BaseModel):
     """搜索网络内容工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(
-        None,
-        description="Clear explanation of why this tool is being used in the current context",
-    )
     query: str = Field(
         ..., description="The search query string to search for on the web"
     )
diff --git a/app/agent/tools/impl/send_local_file.py b/app/agent/tools/impl/send_local_file.py
index e63f2859..00c8f4d9 100644
--- a/app/agent/tools/impl/send_local_file.py
+++ b/app/agent/tools/impl/send_local_file.py
@@ -16,8 +16,6 @@ from app.schemas.types import MessageChannel
 class SendLocalFileInput(BaseModel):
     """发送本地附件工具输入。"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why sending this local file helps the user",)
     file_path: str = Field(
         ...,
         description="Absolute path to the local image or file to send to the user",
diff --git a/app/agent/tools/impl/send_message.py b/app/agent/tools/impl/send_message.py
index 7284a54a..07ff5612 100644
--- a/app/agent/tools/impl/send_message.py
+++ b/app/agent/tools/impl/send_message.py
@@ -14,10 +14,6 @@ from app.schemas.types import NotificationType
 class SendMessageInput(BaseModel):
     """发送消息工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(
-        None,
-        description="Clear explanation of why this tool is being used in the current context",
-    )
     message: Optional[str] = Field(
         None,
         description="The message content to send to the user (should be clear and informative)",
diff --git a/app/agent/tools/impl/send_voice_message.py b/app/agent/tools/impl/send_voice_message.py
index 6ac7383e..482336b0 100644
--- a/app/agent/tools/impl/send_voice_message.py
+++ b/app/agent/tools/impl/send_voice_message.py
@@ -14,10 +14,6 @@ from app.schemas import Notification, NotificationType
 class SendVoiceMessageInput(BaseModel):
     """发送语音消息工具输入。"""
 
-    explanation: Optional[str] = Field(
-        None,
-        description="Clear explanation of why a voice reply is the best fit in the current context",
-    )
     message: str = Field(
         ...,
         description="The spoken content to send back to the user",
diff --git a/app/agent/tools/impl/switch_persona.py b/app/agent/tools/impl/switch_persona.py
index 4ecf7a25..9ad9eebf 100644
--- a/app/agent/tools/impl/switch_persona.py
+++ b/app/agent/tools/impl/switch_persona.py
@@ -14,8 +14,6 @@ from app.log import logger
 class SwitchPersonaInput(BaseModel):
     """切换人格工具的输入参数模型。"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     persona_id: str = Field(
         ...,
         description=(
diff --git a/app/agent/tools/impl/test_site.py b/app/agent/tools/impl/test_site.py
index 4c11a7bd..15c83796 100644
--- a/app/agent/tools/impl/test_site.py
+++ b/app/agent/tools/impl/test_site.py
@@ -13,7 +13,6 @@ from app.log import logger
 
 class TestSiteInput(BaseModel):
     """测试站点连通性工具的输入参数模型"""
-    explanation: Optional[str] = Field(None, description="Clear explanation of why this tool is being used in the current context")
     site_identifier: int = Field(..., description="Site ID to test (can be obtained from query_sites tool)")
 
 
diff --git a/app/agent/tools/impl/transfer_file.py b/app/agent/tools/impl/transfer_file.py
index 7f3cf0bb..c60de886 100644
--- a/app/agent/tools/impl/transfer_file.py
+++ b/app/agent/tools/impl/transfer_file.py
@@ -14,8 +14,6 @@ from app.schemas import FileItem, MediaType
 class TransferFileInput(BaseModel):
     """整理文件或目录工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     file_path: str = Field(
         ...,
         description="Path to the file or directory to transfer (e.g., '/path/to/file.mkv' or '/path/to/directory')",
diff --git a/app/agent/tools/impl/uninstall_plugin.py b/app/agent/tools/impl/uninstall_plugin.py
index b058b372..a41925f6 100644
--- a/app/agent/tools/impl/uninstall_plugin.py
+++ b/app/agent/tools/impl/uninstall_plugin.py
@@ -18,8 +18,6 @@ from app.log import logger
 class UninstallPluginInput(BaseModel):
     """卸载插件工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     plugin_id: str = Field(
         ...,
         description="Exact plugin ID to uninstall. Use query_installed_plugins first to find the correct plugin_id.",
diff --git a/app/agent/tools/impl/update_custom_filter_rule.py b/app/agent/tools/impl/update_custom_filter_rule.py
index 02d4b7cd..6a165905 100644
--- a/app/agent/tools/impl/update_custom_filter_rule.py
+++ b/app/agent/tools/impl/update_custom_filter_rule.py
@@ -23,8 +23,6 @@ from app.schemas.types import SystemConfigKey
 class UpdateCustomFilterRuleInput(BaseModel):
     """更新自定义过滤规则工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     current_rule_id: str = Field(
         ..., description="Existing custom rule ID to update."
     )
diff --git a/app/agent/tools/impl/update_custom_identifiers.py b/app/agent/tools/impl/update_custom_identifiers.py
index 967bf835..bb80b803 100644
--- a/app/agent/tools/impl/update_custom_identifiers.py
+++ b/app/agent/tools/impl/update_custom_identifiers.py
@@ -15,8 +15,6 @@ from app.schemas.types import SystemConfigKey
 class UpdateCustomIdentifiersInput(BaseModel):
     """更新自定义识别词工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     identifiers: List[str] = Field(
         ...,
         description=(
diff --git a/app/agent/tools/impl/update_download_tasks.py b/app/agent/tools/impl/update_download_tasks.py
index 49aa0bcc..715883e0 100644
--- a/app/agent/tools/impl/update_download_tasks.py
+++ b/app/agent/tools/impl/update_download_tasks.py
@@ -14,10 +14,6 @@ from app.log import logger
 class UpdateDownloadTasksInput(BaseModel):
     """更新下载任务工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(
-        None,
-        description="Clear explanation of why this tool is being used in the current context",
-    )
     hash: str = Field(
         ..., description="Task hash (can be obtained from query_download_tasks tool)"
     )
diff --git a/app/agent/tools/impl/update_persona_definition.py b/app/agent/tools/impl/update_persona_definition.py
index a745a560..1e8d2519 100644
--- a/app/agent/tools/impl/update_persona_definition.py
+++ b/app/agent/tools/impl/update_persona_definition.py
@@ -14,8 +14,6 @@ from app.log import logger
 class UpdatePersonaDefinitionInput(BaseModel):
     """更新人格定义工具的输入参数模型。"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     persona_id: str = Field(
         ...,
         description=(
diff --git a/app/agent/tools/impl/update_plugin_config.py b/app/agent/tools/impl/update_plugin_config.py
index 9ce75217..ab5f6787 100644
--- a/app/agent/tools/impl/update_plugin_config.py
+++ b/app/agent/tools/impl/update_plugin_config.py
@@ -15,8 +15,6 @@ from app.log import logger
 class UpdatePluginConfigInput(BaseModel):
     """修改插件配置工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     plugin_id: str = Field(
         ...,
         description="The plugin ID to update. Use query_plugin_config first to inspect the current config.",
diff --git a/app/agent/tools/impl/update_rule_group.py b/app/agent/tools/impl/update_rule_group.py
index ba89f739..e58edb6a 100644
--- a/app/agent/tools/impl/update_rule_group.py
+++ b/app/agent/tools/impl/update_rule_group.py
@@ -25,8 +25,6 @@ from app.schemas.types import SystemConfigKey
 class UpdateRuleGroupInput(BaseModel):
     """更新过滤规则组工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     current_name: str = Field(..., description="Existing rule group name to update.")
     new_name: Optional[str] = Field(
         None,
diff --git a/app/agent/tools/impl/update_site.py b/app/agent/tools/impl/update_site.py
index b0ffeb43..1c8f58c2 100644
--- a/app/agent/tools/impl/update_site.py
+++ b/app/agent/tools/impl/update_site.py
@@ -17,8 +17,6 @@ from app.utils.string import StringUtils
 class UpdateSiteInput(BaseModel):
     """更新站点工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     site_id: int = Field(
         ...,
         description="The ID of the site to update (can be obtained from query_sites tool)",
diff --git a/app/agent/tools/impl/update_site_cookie.py b/app/agent/tools/impl/update_site_cookie.py
index b9f9940d..79d83912 100644
--- a/app/agent/tools/impl/update_site_cookie.py
+++ b/app/agent/tools/impl/update_site_cookie.py
@@ -14,8 +14,6 @@ from app.log import logger
 class UpdateSiteCookieInput(BaseModel):
     """更新站点Cookie和UA工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     site_identifier: int = Field(
         ...,
         description="Site ID to update Cookie and User-Agent for (can be obtained from query_sites tool)",
diff --git a/app/agent/tools/impl/update_subscribe.py b/app/agent/tools/impl/update_subscribe.py
index 6428d648..da243a7e 100644
--- a/app/agent/tools/impl/update_subscribe.py
+++ b/app/agent/tools/impl/update_subscribe.py
@@ -16,8 +16,6 @@ from app.schemas.types import EventType
 class UpdateSubscribeInput(BaseModel):
     """更新订阅工具的输入参数模型"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     subscribe_id: int = Field(
         ...,
         description="The ID of the subscription to update (can be obtained from query_subscribes tool)",
diff --git a/app/agent/tools/impl/update_system_settings.py b/app/agent/tools/impl/update_system_settings.py
index 6d2764d5..9192ce49 100644
--- a/app/agent/tools/impl/update_system_settings.py
+++ b/app/agent/tools/impl/update_system_settings.py
@@ -29,8 +29,6 @@ SettingValue = Optional[Union[list, dict, bool, int, float, str]]
 class UpdateSystemSettingsInput(BaseModel):
     """更新系统设置工具的输入参数模型。"""
 
-    explanation: Optional[str] = Field(None,
-        description="Clear explanation of why this tool is being used in the current context",)
     setting_key: str = Field(
         ...,
         description=(
diff --git a/app/cli.py b/app/cli.py
index f3e7dc58..8cd7c014 100644
--- a/app/cli.py
+++ b/app/cli.py
@@ -559,8 +559,6 @@ def _format_tool_detail(tool: Dict[str, Any]) -> None:
     required = set((tool.get("inputSchema") or {}).get("required") or [])
     fields = []
     for name, schema in properties.items():
-        if name == "explanation":
-            continue
         fields.append(
             (
                 f"{name}*" if name in required else name,
@@ -1133,8 +1131,7 @@ def tool_show(tool_name: str) -> None:
 @click.argument("args", nargs=-1, type=click.UNPROCESSED)
 def tool_run(tool_name: str, args: tuple[str, ...]) -> None:
     """运行指定工具"""
-    arguments = {"explanation": "CLI invocation"}
-    arguments.update(_parse_key_value_pairs(args))
+    arguments = _parse_key_value_pairs(args)
     result = _call_tool(tool_name, arguments, runtime=_backend_runtime())
     if isinstance(result, (dict, list)):
         _print_json(result)
@@ -1152,7 +1149,7 @@ def scheduler_list() -> None:
     """列出调度任务"""
     result = _call_tool(
         "query_schedulers",
-        {"explanation": "List scheduler jobs from local CLI"},
+        {},
         runtime=_backend_runtime(),
     )
     if isinstance(result, list):
@@ -1168,10 +1165,7 @@ def scheduler_run(job_id: str) -> None:
     """立即执行某个调度任务"""
     result = _call_tool(
         "run_scheduler",
-        {
-            "explanation": "Run a scheduler job from local CLI",
-            "job_id": job_id,
-        },
+        {"job_id": job_id},
         runtime=_backend_runtime(),
     )
     if isinstance(result, (dict, list)):
diff --git a/docs/mcp-api.md b/docs/mcp-api.md
index 52b3380c..41651a30 100644
--- a/docs/mcp-api.md
+++ b/docs/mcp-api.md
@@ -128,6 +128,8 @@ MoviePilot 也提供普通 REST API 给前端和自动化客户端使用。所
 
 获取所有可用的MCP工具列表。
 
+工具的 `inputSchema` 只包含实际执行业务所需的参数，不包含用于解释调用原因的通用 `explanation` 参数，以减少 Agent 上下文消耗。
+
 **认证**: 需要API KEY，在请求头中添加 `X-API-KEY: <api_key>` 或在查询参数中添加 `apikey=<api_key>`
 
 **响应示例**:
diff --git a/skills/generate-identifiers/SKILL.md b/skills/generate-identifiers/SKILL.md
index 434e68f6..7c24aab2 100644
--- a/skills/generate-identifiers/SKILL.md
+++ b/skills/generate-identifiers/SKILL.md
@@ -150,7 +150,7 @@ Write the rule using the appropriate format. Ensure:
 Use the `query_custom_identifiers` tool to get all current rules:
 
 ```
-query_custom_identifiers(explanation="Checking existing identifiers before adding new rules to avoid duplicates")
+query_custom_identifiers()
 ```
 
 ### Step 4: Check for Duplicates
@@ -166,7 +166,6 @@ Merge new non-duplicate rules into the existing list, then use `update_custom_id
 
 ```
 update_custom_identifiers(
-    explanation="Adding new identifier rules for [description]",
     identifiers=["existing rule 1", "existing rule 2", "# new comment", "new rule"]
 )
 ```
@@ -178,7 +177,7 @@ update_custom_identifiers(
 If the user wants to verify the rule works, use `recognize_media` to test:
 
 ```
-recognize_media(explanation="Testing recognition after adding identifier", title="the torrent title to test")
+recognize_media(title="the torrent title to test")
 ```
 
 ### Step 7: Report
diff --git a/tests/test_agent_activity_log.py b/tests/test_agent_activity_log.py
index 3248b320..a5f8c6a3 100644
--- a/tests/test_agent_activity_log.py
+++ b/tests/test_agent_activity_log.py
@@ -28,6 +28,13 @@ def _write_activity_log(activity_dir, date_str: str, lines: list[str]) -> None:
     )
 
 
+async def _wait_activity_log_tasks(middleware: ActivityLogMiddleware) -> None:
+    """等待活动日志后台任务完成，避免测试与后台写入竞态。"""
+    tasks = list(middleware._background_tasks)
+    if tasks:
+        await asyncio.gather(*tasks)
+
+
 def test_activity_log_index_counts_entries_without_body(tmp_path):
     """活动日志索引只应包含条目数量，不暴露完整摘要正文。"""
     date_str = datetime.now().strftime("%Y-%m-%d")
@@ -91,19 +98,19 @@ def test_activity_log_abefore_agent_refreshes_existing_state(tmp_path):
 
 def test_activity_log_skips_trivial_greeting_without_llm(tmp_path):
     """无实际任务的寒暄不应调用 LLM，也不应写入活动日志。"""
-    middleware = ActivityLogMiddleware(activity_dir=str(tmp_path))
-    summarize_mock = AsyncMock(return_value="不应写入")
-    append_mock = AsyncMock()
+    async def _run_test():
+        middleware = ActivityLogMiddleware(activity_dir=str(tmp_path))
+        summarize_mock = AsyncMock(return_value="不应写入")
+        append_mock = AsyncMock()
 
-    with (
-        patch(
-            "app.agent.middleware.activity_log._summarize_with_llm",
-            new=summarize_mock,
-        ),
-        patch.object(middleware, "_append_activity", new=append_mock),
-    ):
-        asyncio.run(
-            middleware.aafter_agent(
+        with (
+            patch(
+                "app.agent.middleware.activity_log._summarize_with_llm",
+                new=summarize_mock,
+            ),
+            patch.object(middleware, "_append_activity", new=append_mock),
+        ):
+            await middleware.aafter_agent(
                 {
                     "messages": [
                         HumanMessage(content="你好"),
@@ -112,7 +119,11 @@ def test_activity_log_skips_trivial_greeting_without_llm(tmp_path):
                 },
                 runtime=None,
             )
-        )
+            await _wait_activity_log_tasks(middleware)
+
+        return summarize_mock, append_mock
+
+    summarize_mock, append_mock = asyncio.run(_run_test())
 
     summarize_mock.assert_not_awaited()
     append_mock.assert_not_awaited()
@@ -137,18 +148,18 @@ def test_summarize_with_llm_ignores_skip_marker():
 
 def test_activity_log_records_detailed_summary(tmp_path):
     """有实际工具动作的交互应写入较完整的活动摘要。"""
-    middleware = ActivityLogMiddleware(activity_dir=str(tmp_path))
     summary = (
         "用户要求整理 `/downloads/Show`，助手调用 transfer_file 识别并转移剧集，"
         "结果成功写入目标媒体库。"
     )
 
-    with patch(
-        "app.agent.middleware.activity_log._summarize_with_llm",
-        new=AsyncMock(return_value=summary),
-    ):
-        asyncio.run(
-            middleware.aafter_agent(
+    async def _run_test():
+        middleware = ActivityLogMiddleware(activity_dir=str(tmp_path))
+        with patch(
+            "app.agent.middleware.activity_log._summarize_with_llm",
+            new=AsyncMock(return_value=summary),
+        ):
+            await middleware.aafter_agent(
                 {
                     "messages": [
                         HumanMessage(content="帮我整理 /downloads/Show"),
@@ -170,7 +181,9 @@ def test_activity_log_records_detailed_summary(tmp_path):
                 },
                 runtime=None,
             )
-        )
+            await _wait_activity_log_tasks(middleware)
+
+    asyncio.run(_run_test())
 
     log_files = list(tmp_path.glob("*.md"))
     assert len(log_files) == 1
@@ -179,6 +192,61 @@ def test_activity_log_records_detailed_summary(tmp_path):
     assert "- **" in content
 
 
+def test_activity_log_after_agent_does_not_wait_for_summary(tmp_path):
+    """活动日志摘要生成应在后台执行，不阻塞当前 Agent 会话结束。"""
+
+    async def _slow_summarize(_conversation_text: str) -> str:
+        """模拟较慢的活动摘要生成。"""
+        await asyncio.sleep(0.05)
+        return "用户要求检查下载任务，助手调用工具完成检查。"
+
+    async def _run_test():
+        middleware = ActivityLogMiddleware(activity_dir=str(tmp_path))
+        append_mock = AsyncMock()
+        with (
+            patch(
+                "app.agent.middleware.activity_log._summarize_with_llm",
+                side_effect=_slow_summarize,
+            ) as summarize_mock,
+            patch.object(middleware, "_append_activity", new=append_mock),
+        ):
+            await middleware.aafter_agent(
+                {
+                    "messages": [
+                        HumanMessage(content="帮我检查下载任务"),
+                        AIMessage(
+                            content="",
+                            tool_calls=[
+                                {
+                                    "name": "query_download_tasks",
+                                    "args": {},
+                                    "id": "call_1",
+                                }
+                            ],
+                        ),
+                        ToolMessage(
+                            content='{"success": true}',
+                            tool_call_id="call_1",
+                        ),
+                    ],
+                },
+                runtime=None,
+            )
+            called_before_wait = summarize_mock.await_count
+            pending_before_wait = len(middleware._background_tasks)
+            await _wait_activity_log_tasks(middleware)
+            return called_before_wait, pending_before_wait, summarize_mock, append_mock
+
+    called_before_wait, pending_before_wait, summarize_mock, append_mock = asyncio.run(
+        _run_test()
+    )
+
+    assert called_before_wait == 0
+    assert pending_before_wait == 1
+    summarize_mock.assert_awaited_once()
+    append_mock.assert_awaited_once_with("用户要求检查下载任务，助手调用工具完成检查。")
+
+
 def test_query_activity_logs_filters_by_keyword_and_date(tmp_path):
     """活动日志查询应支持日期和关键词过滤。"""
     _write_activity_log(
diff --git a/tests/test_agent_image_support.py b/tests/test_agent_image_support.py
index 76b00476..2d597367 100644
--- a/tests/test_agent_image_support.py
+++ b/tests/test_agent_image_support.py
@@ -563,7 +563,6 @@ class AgentImageSupportTest(unittest.TestCase):
 
     def test_send_message_input_accepts_image_only_payload(self):
         payload = SendMessageInput(
-            explanation="send poster image",
             image_url="https://example.com/poster.png",
         )
 
@@ -659,7 +658,6 @@ class AgentImageSupportTest(unittest.TestCase):
 
     def test_send_local_file_input_accepts_file_payload(self):
         payload = SendLocalFileInput(
-            explanation="send generated report",
             file_path="/tmp/report.txt",
             message="请下载查看",
         )
diff --git a/tests/test_agent_interaction.py b/tests/test_agent_interaction.py
index 833818da..03aa8148 100644
--- a/tests/test_agent_interaction.py
+++ b/tests/test_agent_interaction.py
@@ -125,6 +125,7 @@ class TestAgentInteraction(unittest.TestCase):
         notification = async_post_message.await_args.args[0]
         self.assertEqual(notification.text, "请选择要执行的操作")
         self.assertEqual(sum(len(row) for row in notification.buttons), 2)
+        self.assertNotIn("description", notification.buttons[0][0])
 
         callback_data = notification.buttons[0][0]["callback_data"]
         _, _, request_id, option_index = callback_data.split(":")
diff --git a/tests/test_agent_skills_middleware.py b/tests/test_agent_skills_middleware.py
index 168e0da4..c8841e5c 100644
--- a/tests/test_agent_skills_middleware.py
+++ b/tests/test_agent_skills_middleware.py
@@ -132,7 +132,6 @@ async def test_skill_tool_call_records_streaming_summary(tmp_path):
         tool_call={
             "args": {
                 "name": "moviepilot-cli",
-                "explanation": "测试加载技能",
             }
         },
     )
@@ -150,7 +149,6 @@ async def test_skill_tool_call_records_streaming_summary(tmp_path):
             "tool_message": "Skill loaded",
             "tool_kwargs": {
                 "name": "moviepilot-cli",
-                "explanation": "测试加载技能",
             },
         }
     ]
diff --git a/tests/test_agent_tool_factory_cache.py b/tests/test_agent_tool_factory_cache.py
index 60bfdeac..1f2c2e16 100644
--- a/tests/test_agent_tool_factory_cache.py
+++ b/tests/test_agent_tool_factory_cache.py
@@ -1,10 +1,18 @@
+import importlib.util
 from types import SimpleNamespace
-from typing import Iterator, Optional
+from pathlib import Path
+from typing import Iterator, Optional, Type
 
 import pytest
+from pydantic import BaseModel
 
+from app.agent.middleware.activity_log import QueryActivityLogInput
+from app.agent.middleware.skills import SkillToolInput
 from app.agent.tools.base import MoviePilotTool
 from app.agent.tools.factory import MoviePilotToolFactory
+from app.agent.tools.impl.ask_user_choice import AskUserChoiceInput, AskUserChoiceTool
+from app.agent.tools.impl.send_local_file import SendLocalFileTool
+from app.agent.tools.impl.send_voice_message import SendVoiceMessageTool
 from app.core.plugin import PluginManager
 from app.utils.singleton import Singleton
 
@@ -56,6 +64,66 @@ def _build_plugin(
     )
 
 
+def _schema_properties(args_schema: Type[BaseModel]) -> dict:
+    """返回工具输入模型的 JSON Schema 属性。"""
+    return args_schema.model_json_schema().get("properties", {})
+
+
+def _load_lexiannot_tool_schemas() -> list[Type[BaseModel]]:
+    """只加载 LexiAnnot schema 文件，避免触发插件包可选依赖。"""
+    schema_path = (
+        Path(__file__).resolve().parents[1]
+        / "app"
+        / "plugins"
+        / "lexiannot"
+        / "schemas.py"
+    )
+    spec = importlib.util.spec_from_file_location(
+        "_test_lexiannot_schemas",
+        schema_path,
+    )
+    assert spec and spec.loader
+    module = importlib.util.module_from_spec(spec)
+    spec.loader.exec_module(module)
+    return [
+        module.VocabularyAnnotatingToolInput,
+        module.QueryAnnotationTasksToolInput,
+    ]
+
+
+def test_agent_tool_schemas_do_not_expose_explanation_parameter() -> None:
+    """所有 Agent 工具输入模型都不应暴露 explanation 参数。"""
+    tool_classes = [
+        *MoviePilotToolFactory.BUILTIN_TOOL_CLASSES,
+        AskUserChoiceTool,
+        SendLocalFileTool,
+        SendVoiceMessageTool,
+    ]
+    middleware_schemas = [
+        SkillToolInput,
+        QueryActivityLogInput,
+    ]
+    plugin_schemas = _load_lexiannot_tool_schemas()
+
+    for tool_class in tool_classes:
+        args_schema = getattr(tool_class, "args_schema", None)
+        if args_schema is None:
+            continue
+        assert "explanation" not in _schema_properties(args_schema), tool_class.name
+
+    for args_schema in middleware_schemas + plugin_schemas:
+        assert "explanation" not in _schema_properties(args_schema), args_schema.__name__
+
+
+def test_ask_user_choice_option_schema_does_not_expose_description() -> None:
+    """询问用户意图工具的选项参数不应暴露 description 字段。"""
+    schema = AskUserChoiceInput.model_json_schema()
+    option_schema = schema["$defs"]["UserChoiceOptionInput"]
+
+    assert "description" not in option_schema["properties"]
+    assert option_schema["required"] == ["label", "value"]
+
+
 def test_plugin_agent_tools_are_cached(plugin_manager: PluginManager) -> None:
     """插件智能体工具注册表应缓存，避免同一轮启动反复询问插件实例。"""
     calls: list[int] = []
diff --git a/tests/test_agent_tool_streaming.py b/tests/test_agent_tool_streaming.py
index d408b35a..fd665b84 100644
--- a/tests/test_agent_tool_streaming.py
+++ b/tests/test_agent_tool_streaming.py
@@ -49,6 +49,10 @@ class DummyTool(MoviePilotTool):
     name: str = "dummy_tool"
     description: str = "Dummy tool for streaming tests."
 
+    def get_tool_message(self, **kwargs) -> str:
+        """返回固定工具执行提示。"""
+        return "run test tool"
+
     async def run(self, **kwargs) -> str:
         """返回固定工具执行结果。"""
         return "ok"
@@ -67,7 +71,7 @@ class TestAgentToolStreaming:
         tool.set_stream_handler(handler)
 
         with patch.object(settings, "AI_AGENT_VERBOSE", False):
-            result = await tool._arun(explanation="run test tool")
+            result = await tool._arun()
 
         buffered_message = await handler.take()
         return result, buffered_message
@@ -103,7 +107,7 @@ class TestAgentToolStreaming:
             tool.set_stream_handler(handler)
 
             with patch.object(settings, "AI_AGENT_VERBOSE", False):
-                await tool._arun(explanation="run test tool")
+                await tool._arun()
 
             handler.emit("已经拿到结果")
             return await handler.take()
@@ -470,7 +474,7 @@ class TestAgentToolStreaming:
                     DummyTool, "send_tool_message", new_callable=AsyncMock
                 ) as send_tool_message,
             ):
-                result = await tool._arun(explanation="run test tool")
+                result = await tool._arun()
                 buffered_message = await handler.take()
                 return result, buffered_message, send_tool_message
 
@@ -497,7 +501,7 @@ class TestAgentToolStreaming:
                     DummyTool, "send_tool_message", new_callable=AsyncMock
                 ) as send_tool_message,
             ):
-                result = await tool._arun(explanation="run test tool")
+                result = await tool._arun()
                 buffered_message = await handler.take()
                 return result, buffered_message, send_tool_message