Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint and idempotentHint, so the description adds value by explaining the state-dependent return values: 'authenticated:true and empty pending[]' versus 'connect_url and per-install URLs'. This goes beyond the annotation hints and clarifies what the tool actually returns in different scenarios, though it could describe edge cases like partial connections.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.