"""Same four tools via lowlevel.Server — inputSchema is hand-written JSON Schema.""" from typing import Any import mcp_types as types from mcp.server.context import ServerRequestContext from mcp.server.lowlevel import Server from stories._hosting import run_server_from_args # With lowlevel.Server there is no reflection layer: you author the JSON Schema # yourself and validate/unpack `params.arguments` in the handler. PERSON_SCHEMA: dict[str, Any] = { "type": "object", "properties": {"name": {"type": "string"}, "title": {"type": "string"}}, "required": ["name"], } TOOLS = [ types.Tool( name=f"greet_{variant}", description=f"Greet ({variant} input shape)", input_schema={"type": "object", "properties": {"who": PERSON_SCHEMA}, "required": ["who"]}, ) for variant in ("pydantic", "typeddict", "dataclass") ] TOOLS.append( types.Tool( name="greet_dict", description="Greet (free-form dict input)", input_schema={ "type": "object", "properties": {"who": {"type": "object", "additionalProperties": True}}, "required": ["who"], }, ) ) def build_server() -> Server[Any]: async def list_tools( ctx: ServerRequestContext[Any], params: types.PaginatedRequestParams | None ) -> types.ListToolsResult: return types.ListToolsResult(tools=TOOLS) async def call_tool(ctx: ServerRequestContext[Any], params: types.CallToolRequestParams) -> types.CallToolResult: assert params.arguments is not None who = params.arguments["who"] text = f"Hello {who['name']}, my {who.get('title', 'friend')}" return types.CallToolResult(content=[types.TextContent(text=text)]) return Server("schema-validators-example", on_list_tools=list_tools, on_call_tool=call_tool) if __name__ == "__main__": run_server_from_args(build_server)