Question: Tool list changed notification

[enesgules]

https://modelcontextprotocol.io/specification/2025-06-18/server/tools#list-changed-notification

Does the SDK support this feature?

When we deployed a newer version of the Context7 MCP server with new tool parameters we had a bunch of users reporting issues. Would love to use this feature in the future to prevent such cases.

[chipgpt]

I have submitted a PR for this #1068

[felixweinberger]

Yes, the SDK supports this!

// McpServer - notification sent automatically when registering tools at runtime
mcpServer.registerTool("new-tool", { description: "..." }, async () => { ... });

// Or send manually
mcpServer.sendToolListChanged();

// Low-level Server
server.sendToolListChanged();

Clients can listen for the notification:

client.setNotificationHandler(ToolListChangedNotificationSchema, () => {
  // Refresh tool list
  client.listTools();
});

This should be added to our documentation - marking as good first issue.