Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover destructiveness (destructiveHint=true) and idempotence (idempotentHint=true). The description adds minimal behavioral context (e.g., 'clear sensitive data') but does not go beyond what annotations imply. The bar is lower with annotations present, and the description contributes some value, though not substantial.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.