Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, and destructiveHint. The description adds meaningful conditional behavior: when all providers are connected vs. when credentials are missing, including the return of connect_url and per-install URLs. This goes beyond the annotations to clarify expected states.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.