feat: Add mcp router as a built-in tool (#41)

Author: songyichun123

config.yaml.example

@@ -40,6 +40,8 @@ tool:
   las:
     url: #mcp sse url
     dataset_id:  #dataset name
+  mcp_router:
+    url: #mcp sse/streamable-http url
 
 
 observability:

veadk/tools/builtin_tools/mcp_router.py

@@ -0,0 +1,22 @@
+# Copyright (c) 2025 Beijing Volcano Engine Technology Co., Ltd. and/or its affiliates.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from google.adk.tools.mcp_tool.mcp_toolset import MCPToolset
+
+from veadk.config import getenv
+from veadk.utils.mcp_utils import get_mcp_params
+
+url = getenv("TOOL_MCP_ROUTER_URL")
+
+mcp_router = MCPToolset(connection_params=get_mcp_params(url=url))