Semanti Kernel as MCP server - Tools discovery endpoint

[OctavianHome]

I configured Semantic Kernel as an MCP server by following documentation from this repo (sse):

starlette_app = Starlette(
    debug=True,
    routes=[
        Route("/sse", endpoint=handle_sse),
        Mount("/messages/", app=sse.handle_post_message),
    ],
)

It is working fine integrated into GitHub Copilot.

Which is the endpoint to get the list of tools?
Thanks

[sophialagerkranspandey]

This should be detailed in a standard endpoint to get a list of tools. Are you using Python or .NET? Looping in @SergeyMenshykh @eavanvalkenburg

[eavanvalkenburg]

The endpoint for list tools gets created automatically by the underlying MCP package, but only if you have functions registered in your kernel. You can use the inspector mcp tool to validate (https://modelcontextprotocol.io/docs/tools/inspector)

[OctavianHome]

I would like to create a VSCode extension which connects with an MCP server exposed by the Semantic Kernel.
I don't know how to make a request (URL, protocol, payload) to fetch the existing tools exposed.
Could you please give me an example?
Thanks

[eavanvalkenburg]

there is nothing needed to do that, just create your kernel, add functions, and then call kernel.as_mcp_server and run that, like shown here: https://github.com/microsoft/semantic-kernel/blob/main/python/samples/demos/mcp_server/sk_mcp_server.py Then you can choose to run that with Stdio and UV, or with python as the command. Or you start the server and connect to localhost:. You endpoint is tools/list as shown here: https://modelcontextprotocol.io/specification/2025-03-26/server/tools. But I'm not sure what the full address is, that is kind of obscure, you might be able to just google around to find it, all MCP clients should just be able to connect regardless, so make sure to leverage something rather then doing HTTP requests yourself.

[OctavianHome]

I've already followed https://github.com/microsoft/semantic-kernel/blob/main/python/samples/demos/mcp_server/sk_mcp_server.py and the MCP server is working as expected (server-side events approach).
But implementing of discovery tools https://modelcontextprotocol.io/specification/2025-03-26/server/tools is indeed my current issue...
I can't find a clear JSON-RPC example of how to do it - I can find "payload" examples only but not the "full" example: URL, payload, protocol.

[eavanvalkenburg]

@OctavianHome maybe you can construct it from here: https://github.com/modelcontextprotocol/python-sdk/blob/b4c7db6a50a5c88bae1db5c1f7fba44d16eebc6e/src/mcp/client/session.py#L314