Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare destructiveHint=true and readOnlyHint=false. The description adds the irreversibility nuance of 'permanently' and targets the archived mailbox specifically, but it does not disclose potential cascading effects, authorization needs, or what happens to associated data.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.