[BUG] MCP ToolCollection raises KeyError: 'type'

[gonzoramos]

Describe the bug
When loading an MCP tool (e.g. mcp_server_tavily), an exception occurs in _generate_tool_inputs(...). key "type" is not found.

Code to reproduce the error

# Load an MCP server like so
server_parameters = StdioServerParameters(
    command="python",
    args=["mcp_server_tavily.py"],
)

# then see what tools it exposes
with ToolCollection.from_mcp(server_parameters) as toolset:

    for tool in [*toolset.tools]:
        print(tool.name)

Error logs (if any)

  File ".../lib/python3.11/site-packages/mcpadapt/smolagents_adapter.py", line 30, in <dictcomp>
    k: {"type": v["type"], "description": v.get("description", "")}
                ~^^^^^^^^
KeyError: 'type'

Expected behavior
No exception

Packages version:
smolagents==1.8.1

Additional context
Add any other context about the problem here.

[gonzoramos]

This edit fixed the exception, but I am not sure if it causes a regression:

def _generate_tool_inputs(resolved_json_schema: dict[str, Any]) -> dict[str, str]:
    """
    takes an json_schema as used in the MCP protocol and return an inputs dict for
    smolagents tools. see AUTHORIZED_TYPES in smolagents.tools for the types allowed.
    Note that we consider the json_schema to already have $ref resolved with jsonref for
    example.
    """
    
    # debuging
    items = resolved_json_schema.items()
    print(items)

    return {
        # TODO: use google-docstring-parser to parse description of args and pass it here...
        k: {"type": v["type"] if "type" in v else "object", "description": v.get("description", "")}
        for k, v in resolved_json_schema.items()
    }

[aymeric-roucher]

@grll what do you think, should we merge this change?

[sysradium]

I would carefully check beforehand : 🤔

[grll]

I need to find the root cause first, is it because we are not exposing the type as we should in mcpadapt?

[phirsch]

FWIW, during troubleshooting when I encountered this bug, I found that other tools like @wong2/mcp-cli also complained about missing type fields with the MCP(s) I used (in my case https://github.com/YUZongmin/semantic-scholar-fastmcp-mcp-server, https://github.com/afrise/academic-search-mcp-server, https://github.com/ivo-toby/mcp-openapi-server).

[grll]

Hey there I have got some news on this issue @murawakimitsuhiro flagged it as mcpadapt not correctly handling mcp server where some parameters are nullable, see grll/mcpadapt#10. We are working on a fix.

[grll]

We have successfully merged the work of @murawakimitsuhiro which means this should be fixed by bumping mcpadapt to 0.0.15 and above.

[albertvillanova]

Thanks for the fix, @murawakimitsuhiro and @grll! 🤗