Log exception before returning tool call error result

Fixes #3266

Author: fabianlange

src/mcp/server/mcpserver/server.py

@@ -421,6 +421,7 @@ async def _handle_call_tool(
         except MCPError:
             raise
         except Exception as e:
+            logger.exception("Tool call failed")
             return CallToolResult(content=[TextContent(type="text", text=str(e))], is_error=True)
 
     async def _handle_list_resources(