diff --git a/backend/app.py b/backend/app.py
index 60d0d4f..299dc47 100644
--- a/backend/app.py
+++ b/backend/app.py
@@ -16,7 +16,7 @@ from contextlib import asynccontextmanager
 
 import settings
 import uvicorn
-from db.session import sync_interface_definitions
+from db.session import sync_default_tools, sync_interface_definitions
 from fastapi import FastAPI
 from fastapi.middleware.cors import CORSMiddleware
 
@@ -36,6 +36,7 @@ from routes import (
 @asynccontextmanager
 async def lifespan(_app: FastAPI):
     await sync_interface_definitions()
+    await sync_default_tools()
     yield
 
 
diff --git a/backend/db/session.py b/backend/db/session.py
index 8367c59..000916c 100644
--- a/backend/db/session.py
+++ b/backend/db/session.py
@@ -45,3 +45,39 @@ async def sync_interface_definitions() -> None:
                     "field_schema": json.dumps({"fields": definition["fields"]}),
                 },
             )
+
+
+async def sync_default_tools() -> None:
+    """Ensure system-provided reusable tools exist without overwriting edits."""
+    async with engine.begin() as conn:
+        await conn.execute(
+            text(
+                "INSERT INTO tools "
+                "(id, name, function_name, type, description, definition, secrets, status) "
+                "VALUES ("
+                ":id, :name, :function_name, :type, :description, "
+                "CAST(:definition AS jsonb), CAST(:secrets AS jsonb), :status"
+                ") "
+                "ON CONFLICT (function_name) DO NOTHING"
+            ),
+            {
+                "id": "tool_end_call_default",
+                "name": "结束对话",
+                "function_name": "end_call",
+                "type": "end_call",
+                "description": "当用户明确要求结束对话，或任务已完成时调用。",
+                "definition": json.dumps(
+                    {
+                        "schema_version": 1,
+                        "type": "end_call",
+                        "config": {
+                            "message_type": "none",
+                            "custom_message": "",
+                            "capture_reason": True,
+                        },
+                    }
+                ),
+                "secrets": "{}",
+                "status": "active",
+            },
+        )