Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare destructiveHint=true, idempotentHint=true, and readOnlyHint=false. The description earns credit by disambiguating what 'destructive' means here: it stops only new deliveries and leaves the provider-side sheet, database, or channel intact, which a bare destructiveHint would not convey.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.