README.md

AgentTool with MCP Demo (SSE Mode)

This demo shows how AgentTool works with MCP (Model Context Protocol) toolsets using SSE mode.

SSE vs Stdio Mode

This demo uses SSE (Server-Sent Events) mode where the MCP server runs as a separate HTTP server:

• Remote connection - Connects to server via HTTP
• Separate process - Server must be started manually
• Network communication - Uses HTTP/SSE for messaging

For the stdio (subprocess) version, see mcp_in_agent_tool_stdio.

Setup

Start the MCP simple-tool server in SSE mode (in a separate terminal):

# Run the server using uvx (no installation needed)
# Port 3000 avoids conflict with adk web (which uses 8000)
uvx --from 'git+https://github.com/modelcontextprotocol/python-sdk.git#subdirectory=examples/servers/simple-tool' \
    mcp-simple-tool --transport sse --port 3000

The server should be accessible at http://localhost:3000/sse.

Running the Demo

adk web contributing/samples

Then select mcp_in_agent_tool_remote from the list and interact with the agent.

Try These Prompts

This demo uses Gemini 2.5 Flash as the model. Try these prompts:

1. Check available tools:

   What tools do you have access to?
   

2. Fetch and summarize JSON Schema specification:

   Use the mcp_helper to fetch https://json-schema.org/specification and summarize the key features of JSON Schema
   

Architecture

main_agent (root_agent)
  │
  └── AgentTool wrapping:
        │
        └── mcp_helper (sub_agent)
              │
              └── McpToolset (SSE connection)
                    │
                    └── http://localhost:3000/sse
                          │
                          └── MCP simple-tool server
                                │
                                └── Website Fetcher Tool

Related

• Issue: #1112 - Using agent as tool outside of adk web doesn't exit cleanly
• Related Issue: #929 - LiteLLM giving error with OpenAI models and Grafana's MCP server
• Stdio Version: mcp_in_agent_tool_stdio - Uses local subprocess connection