fix: improve maintenance and synchronize live conversations

backend/app/models/schemas/mcp_tool.py

@@ -16,10 +16,9 @@ limitations under the License.
 
 from datetime import datetime
 from pydantic import BaseModel, Field, field_serializer, validator
-from typing import List, Optional, Dict, Union
+from typing import List, Optional, Dict
 from enum import Enum
 from uuid import UUID
-from app.models.mcp_tool import MCPTransportType
 
 
 class MCPTransportTypeEnum(str, Enum):