Functions with *args or **kwargs are not supported as tools

[DaveBben]

When using the entity_action tool, the Model trying to supply "params" as another argument. This leads to a 400 error when trying to make a request to home assistant. The agent doesn't understand that params can be a variable list of key words. Something with the schema is confusing it.

Upon further inspection, it seems like FastMCP doesn't support kwargs for tools:

Functions with *args or **kwargs are not supported as tools. This restriction exists because FastMCP needs to generate a complete parameter schema for the MCP protocol, which isn’t possible with variable argument lists.

Updated the entity_action so that it takes a dictionary instead. This solves the issue on tool calling and doesn't produce 400 error.

[voska]

Thanks @DaveBben. Merging.

Take a look at the dev tag for a more reliable mcp experience :)