Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare destructiveHint=true, readOnlyHint=false and idempotentHint=true, so the safety profile is covered. The description adds value beyond that: it explains the downstream consequence (flows stop emailing the address) and an auth requirement (owners/admins) that no annotation expresses. It omits reversibility/how to restore the recipient.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.