mcp-tool-integrator

mcp-tool-integrator

Pull tools from an MCP server into your ADK 2.0 agent. ADK supports both stdio (subprocess) and HTTP MCP transports.

When to use

• Reuse an existing MCP server (filesystem, GitHub, Slack, custom)
• Avoid re-implementing tools that already exist as MCP servers
• Standardized cross-tool ecosystem

Stdio transport (subprocess MCP server)

from google.adk.agents import LlmAgent
from google.adk.tools.mcp_tool import McpToolset, StdioServerParameters

filesystem_toolset = McpToolset(
    connection_params=StdioServerParameters(
        command="npx",
        args=["-y", "@modelcontextprotocol/server-filesystem", "/tmp/workspace"],
    ),
)

root_agent = LlmAgent(
    name="file_assistant",
    model="gemini-2.5-flash",
    instruction="Help the user manage files in /tmp/workspace.",
    tools=[filesystem_toolset],
)

HTTP transport

from google.adk.tools.mcp_tool import McpToolset, SseServerParameters

remote_toolset = McpToolset(
    connection_params=SseServerParameters(
        url="https://mcp.example.com/sse",
        headers={"Authorization": "Bearer ${MCP_TOKEN}"},
    ),
)

Filtering exposed tools

The MCP server might expose 20 tools but the agent only needs 3:

filesystem_toolset = McpToolset(
    connection_params=StdioServerParameters(...),
    tool_filter=["read_file", "write_file", "list_directory"],
)

Lifecycle

• Stdio servers spawn on agent init, terminate on agent shutdown
• HTTP servers maintain SSE connections; ADK handles reconnect on disconnect
• Use async with McpToolset(...) as toolset in scripts to ensure cleanup

Common MCP servers to integrate

Server	Purpose
@modelcontextprotocol/server-filesystem	File ops
@modelcontextprotocol/server-github	GitHub API
@modelcontextprotocol/server-postgres	DB queries
@modelcontextprotocol/server-puppeteer	Browser automation
Custom MCP	Your internal services

Validation

• MCP server starts cleanly (npx <server> --help works)
• Tool filter names match server output (tools/list request)
• Auth tokens in env, never hard-coded
• Test: adk web then ask agent to list available tools