Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare destructiveHint=true and readOnlyHint=false, but the description adds material context: there is no undo, and the call will REFUSE under two specific conditions. This tells the agent both the consequence and the failure modes, well beyond what the structured hints provide.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.