Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, and the description adds meaningful state-specific context: it reveals that the response shape varies based on connection state, including authenticated, pending, and connect_url fields. This goes beyond the basic safety profile provided by annotations.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.