`McpServer` does not implement server-side pagination for list operations

[riccardorispoli]

Summary

The high-level McpServer class does not implement cursor-based pagination for tools/list, resources/list, resources/templates/list, or prompts/list. All registered items are returned in a single response regardless of set size.

Spec Reference

The MCP pagination specification defines an opaque cursor-based pagination model where:

• Servers return a page of results along with an optional nextCursor field
• Clients continue paginating by including the cursor in subsequent requests
• Page size is determined by the server

The following operations are expected to support pagination:

• resources/list
• resources/templates/list
• prompts/list
• tools/list

Current Behavior

In mcp.ts, all three list handlers return the complete set without reading the cursor request parameter or returning nextCursor:

// tools/list — returns everything
this.server.setRequestHandler('tools/list', (): ListToolsResult => ({
    tools: Object.entries(this._registeredTools).filter(...).map(...)
}));

// resources/list — returns everything
this.server.setRequestHandler('resources/list', async (_request, ctx) => {
    // ...
    return { resources: [...resources, ...templateResources] };
});

// prompts/list — returns everything
this.server.setRequestHandler('prompts/list', (): ListPromptsResult => ({
    prompts: Object.entries(this._registeredPrompts).filter(...).map(...)
}));

Notes

• The client (packages/client) already handles paginated responses correctly (loops on nextCursor).
• The type system already defines nextCursor in PaginatedResultSchema (schemas.ts).
• Users can work around this by using the low-level Server class and implementing their own list handlers with cursor logic, but McpServer provides no built-in mechanism or configuration for it.

I'd be happy to open a PR for this if the maintainers are aligned with the need.