MCP Apps UI resources

Why it matters

MCP Apps let an agent host show an interactive view of a tool result. The host can render the view only when the server links a ui:// resource and serves it as text/html;profile=mcp-app.

How to fix it

Link each tool view to a ui:// resource and serve it with the MCP App media type.

1. Add _meta.ui.resourceUri with a ui:// URI to each tool that has a view.

   {"name": "show_chart", "_meta": {"ui": {"resourceUri": "ui://charts/view"}}}

2. Answer resources/read for that URI with mimeType text/html;profile=mcp-app and the HTML in text.

Verify

Run a new scan for this checkpoint: