Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare destructiveHint=true and idempotentHint=true, so the description doesn't need to restate these. It adds the motivation of 'clear sensitive data' but does not disclose additional behavioral traits such as error handling when the key doesn't exist or whether deletion is permanent. Given the annotations cover the safety profile, this is adequate but not rich.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.