Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations declare readOnlyHint=true, and the description explains why that is truthful: it 'returns config only — the actual install happens when you complete the sign-in in your client.' It goes well beyond the annotations by enumerating the three distinct result statuses (purchase_required, needs_input, external_mcp_server), the hosted URL format, and the fact that FindAgent is not in the loop for external listings.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.