import { z } from "zod";
import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import {
CallToolResult,
ContentBlock,
} from "@modelcontextprotocol/sdk/types.js";
// Tool input schema
const GetStructuredContentInputSchema = {
location: z
.enum(["New York", "Chicago", "Los Angeles"])
.describe("Choose city"),
};
// Tool output schema
const GetStructuredContentOutputSchema = z.object({
temperature: z.number().describe("Temperature in celsius"),
conditions: z.string().describe("Weather conditions description"),
humidity: z.number().describe("Humidity percentage"),
});
// Tool configuration
const name = "get-structured-content";
const config = {
title: "Get Structured Content Tool",
description:
"Returns structured content along with an output schema for client data validation",
inputSchema: GetStructuredContentInputSchema,
outputSchema: GetStructuredContentOutputSchema,
};
/**
* Registers the 'get-structured-content' tool.
*
* The registered tool processes incoming arguments using a predefined input schema,
* generates structured content with weather information including temperature,
* conditions, and humidity, and returns both backward-compatible content blocks
* and structured content in the response.
*
* The response contains:
* - `content`: An array of content blocks, presented as JSON stringified objects.
* - `structuredContent`: A JSON structured representation of the weather data.
*
* @param {McpServer} server - The McpServer instance where the tool will be registered.
*/
export const registerGetStructuredContentTool = (server: McpServer) => {
server.registerTool(name, config, async (args): Promise<CallToolResult> => {
// Get simulated weather for the chosen city
let weather;
switch (args.location) {
case "New York":
weather = {
temperature: 33,
conditions: "Cloudy",
humidity: 82,
};
break;
case "Chicago":
weather = {
temperature: 36,
conditions: "Light rain / drizzle",
humidity: 82,
};
break;
case "Los Angeles":
weather = {
temperature: 73,
conditions: "Sunny / Clear",
humidity: 48,
};
break;
}
const backwardCompatibleContentBlock: ContentBlock = {
type: "text",
text: JSON.stringify(weather),
};
return {
content: [backwardCompatibleContentBlock],
structuredContent: weather,
};
});
};
