Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already provide readOnlyHint=true and destructiveHint=false, and the description adds value by explaining the exact return payloads in different states (all providers connected vs missing credentials). It also discloses the presence of connect_url, per-install URLs, and the pending[] array, offering transparency beyond annotations.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.