Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare destructiveHint=true, readOnlyHint=false, and idempotentHint=true, covering the safety profile. The description adds minimal extra behavioral context beyond 'clear sensitive data' and doesn't disclose error handling or permanence details. With annotations, this is acceptable but not additive.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.