Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare destructiveHint=true and readOnlyHint=false, so the destructive nature is signaled. The description adds context that this clears previously stored memories and is for stale context or sensitive data, which goes beyond the raw annotation. It does not contradict annotations, and the idempotentHint is consistent with a delete-by-key operation.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.