Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already indicate readOnlyHint, idempotentHint, and destructiveHint false. The description adds value by explaining the exact response states: authenticated:true with empty pending[] when all connected, and connect_url plus per-install URLs when credentials are missing. This provides behavioral transparency beyond the schema.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.