Refactor McpServer tool registration API

- Remove tool() overload that takes a config object with callback - Add new registerTool() method that separates config from callback - Extract common tool registration logic into _createRegisteredTool() helper - Update all tests to use registerTool() for tools with output schemas - Update examples to use registerTool() and high-level Client API - Add comment noting that output schema validation only works with high-level API This change improves API clarity by using a distinct method for tools with output schemas while maintaining backward compatibility. 🤖 Generated with [Claude Code](https://claude.ai/code) Co-Authored-By: Claude <noreply@anthropic.com>

Author: bhosmer-ant

src/examples/server/mcpServerOutputSchema.ts

@@ -16,25 +16,28 @@ const server = new McpServer(
 );
 
 // Define a tool with structured output - Weather data
-server.tool("get_weather", {
- description: "Get weather information for a city",
- inputSchema:{
- city: z.string().describe("City name"),
- country: z.string().describe("Country code (e.g., US, UK)")
- },
- outputSchema: {
- temperature: z.object({
- celsius: z.number(),
- fahrenheit: z.number()
- }),
- conditions: z.enum(["sunny", "cloudy", "rainy", "stormy", "snowy"]),
- humidity: z.number().min(0).max(100),
- wind: z.object({
- speed_kmh: z.number(),
- direction: z.string()
- })
+server.registerTool(
+ "get_weather",
+ {
+ description: "Get weather information for a city",
+ inputSchema:{
+ city: z.string().describe("City name"),
+ country: z.string().describe("Country code (e.g., US, UK)")
+ },
+ outputSchema: {
+ temperature: z.object({
+ celsius: z.number(),
+ fahrenheit: z.number()
+ }),
+ conditions: z.enum(["sunny", "cloudy", "rainy", "stormy", "snowy"]),
+ humidity: z.number().min(0).max(100),
+ wind: z.object({
+ speed_kmh: z.number(),
+ direction: z.string()
+ })
+ },
  },
- callback: async ({ city, country }) => {
+ async ({ city, country }) => {
  // Parameters are available but not used in this example
  void city;
  void country;
@@ -57,7 +60,7 @@ server.tool("get_weather", {
  }
  };
  }
-});
+);
 
 async function main() {
  const transport = new StdioServerTransport();

src/examples/server/testOutputSchemaServers.ts

@@ -7,7 +7,6 @@
 
 import { Client } from "../../client/index.js";
 import { StdioClientTransport } from "../../client/stdio.js";
-import { ListToolsResultSchema, CallToolResultSchema } from "../../types.js";
 
 async function main() {
  const serverPath = process.argv[2];
@@ -39,9 +38,7 @@ async function main() {
 
  // List available tools
  console.log("Listing available tools...");
- const toolsResult = await client.request({
- method: "tools/list"
- }, ListToolsResultSchema);
+ const toolsResult = await client.listTools();
 
  console.log("Available tools:");
  for (const tool of toolsResult.tools) {
@@ -56,16 +53,15 @@ async function main() {
 
  // Call the weather tool
  console.log("\nCalling get_weather tool...");
- const weatherResult = await client.request({
- method: "tools/call",
- params: {
- name: "get_weather",
- arguments: {
- city: "London",
- country: "UK"
- }
+ // Note: Output schema validation only works when using the high-level Client API
+ // methods like callTool(). Low-level protocol requests do not validate the response.
+ const weatherResult = await client.callTool({
+ name: "get_weather",
+ arguments: {
+ city: "London",
+ country: "UK"
  }
- }, CallToolResultSchema);
+ });
 
  console.log("\nWeather tool result:");
  if (weatherResult.structuredContent) {

src/server/mcp.test.ts

@@ -463,14 +463,14 @@ describe("tool()", () => {
  );
 
  // new api
- mcpServer.tool(
+ mcpServer.registerTool(
  "test (new api)",
- { 
- inputSchema: { name: z.string(), value: z.number() }, 
-  callback: async ({ name, value }) => ({
-  content: [{ type: "text", text: `${name}: ${value}` }],
- }),
- }
+ {
+ inputSchema: { name: z.string(), value: z.number() },
+ },
+ async ({ name, value }) => ({
+ content: [{ type: "text", text: `${name}: ${value}` }],
+ })
  );
 
  const [clientTransport, serverTransport] =
@@ -525,17 +525,20 @@ describe("tool()", () => {
  }));
 
  // new api
- mcpServer.tool("test (new api)", {
- description: "Test description",
- callback: async () => ({
+ mcpServer.registerTool(
+ "test (new api)",
+ {
+ description: "Test description",
+ },
+ async () => ({
  content: [
  {
  type: "text" as const,
  text: "Test response",
  },
  ],
  })
- });
+ );
 
 
  const [clientTransport, serverTransport] =
@@ -582,17 +585,20 @@ describe("tool()", () => {
  ],
  }));
 
- mcpServer.tool("test (new api)", {
- annotations: { title: "Test Tool", readOnlyHint: true },
- callback: async () => ({
+ mcpServer.registerTool(
+ "test (new api)",
+ {
+ annotations: { title: "Test Tool", readOnlyHint: true },
+ },
+ async () => ({
  content: [
  {
  type: "text" as const,
  text: "Test response",
  },
  ],
- }),
- });
+ })
+ );
 
  const [clientTransport, serverTransport] =
  InMemoryTransport.createLinkedPair();
@@ -638,13 +644,16 @@ describe("tool()", () => {
  })
  );
 
- mcpServer.tool("test (new api)", {
- inputSchema: { name: z.string() },
- annotations: { title: "Test Tool", readOnlyHint: true },
- callback: async ({ name }) => ({
+ mcpServer.registerTool(
+ "test (new api)",
+ {
+ inputSchema: { name: z.string() },
+ annotations: { title: "Test Tool", readOnlyHint: true },
+ },
+ async ({ name }) => ({
  content: [{ type: "text", text: `Hello, ${name}!` }]
  })
- });
+ );
 
  const [clientTransport, serverTransport] =
  InMemoryTransport.createLinkedPair();
@@ -694,14 +703,17 @@ describe("tool()", () => {
  })
  );
 
- mcpServer.tool("test (new api)", {
- description: "A tool with everything",
- inputSchema: { name: z.string() },
- annotations: { title: "Complete Test Tool", readOnlyHint: true, openWorldHint: false },
- callback: async ({ name }) => ({
+ mcpServer.registerTool(
+ "test (new api)",
+ {
+ description: "A tool with everything",
+ inputSchema: { name: z.string() },
+ annotations: { title: "Complete Test Tool", readOnlyHint: true, openWorldHint: false },
+ },
+ async ({ name }) => ({
  content: [{ type: "text", text: `Hello, ${name}!` }]
  })
- });
+ );
 
  const [clientTransport, serverTransport] =
  InMemoryTransport.createLinkedPair();
@@ -757,14 +769,17 @@ describe("tool()", () => {
  })
  );
 
- mcpServer.tool("test (new api)", {
- description: "A tool with everything but empty params",
- inputSchema: {},
- annotations: { title: "Complete Test Tool with empty params", readOnlyHint: true, openWorldHint: false },
- callback: async () => ({
+ mcpServer.registerTool(
+ "test (new api)",
+ {
+ description: "A tool with everything but empty params",
+ inputSchema: {},
+ annotations: { title: "Complete Test Tool with empty params", readOnlyHint: true, openWorldHint: false },
+ },
+ async () => ({
  content: [{ type: "text" as const, text: "Test response" }]
  })
- });
+ );
 
  const [clientTransport, serverTransport] =
  InMemoryTransport.createLinkedPair();
@@ -834,20 +849,23 @@ describe("tool()", () => {
  }),
  );
 
- mcpServer.tool("test (new api)", {
- inputSchema: {
- name: z.string(),
- value: z.number(),
+ mcpServer.registerTool(
+ "test (new api)",
+ {
+ inputSchema: {
+ name: z.string(),
+ value: z.number(),
+ },
  },
- callback: async ({ name, value }) => ({
+ async ({ name, value }) => ({
  content: [
  {
  type: "text",
  text: `${name}: ${value}`,
  },
  ],
- }),
- });
+ })
+ );
 
  const [clientTransport, serverTransport] =
  InMemoryTransport.createLinkedPair();
@@ -958,7 +976,7 @@ describe("tool()", () => {
  );
 
  // Register a tool with outputSchema
- mcpServer.tool(
+ mcpServer.registerTool(
  "test",
  {
  description: "Test tool with structured output",
@@ -970,14 +988,14 @@ describe("tool()", () => {
  resultType: z.string(),
  timestamp: z.string()
  },
- callback: async ({ input }) => ({
- structuredContent: {
- processedInput: input,
- resultType: "structured",
- timestamp: "2023-01-01T00:00:00Z"
- },
- }),
  },
+ async ({ input }) => ({
+ structuredContent: {
+ processedInput: input,
+ resultType: "structured",
+ timestamp: "2023-01-01T00:00:00Z"
+ },
+ })
  );
 
  const [clientTransport, serverTransport] =
@@ -1061,7 +1079,7 @@ describe("tool()", () => {
  );
 
  // Register a tool with outputSchema that returns invalid data
- mcpServer.tool(
+ mcpServer.registerTool(
  "test",
  {
  description: "Test tool with invalid structured output",
@@ -1073,15 +1091,15 @@ describe("tool()", () => {
  resultType: z.string(),
  timestamp: z.string()
  },
- callback: async ({ input }) => ({
- structuredContent: {
- processedInput: input,
- resultType: "structured",
- // Missing required 'timestamp' field
- someExtraField: "unexpected" // Extra field not in schema
- },
- }),
  },
+ async ({ input }) => ({
+ structuredContent: {
+ processedInput: input,
+ resultType: "structured",
+ // Missing required 'timestamp' field
+ someExtraField: "unexpected" // Extra field not in schema
+ },
+ })
  );
 
  const [clientTransport, serverTransport] =