Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already establish readOnlyHint, idempotentHint, and destructiveHint, so the safety burden is covered. The description adds the no-save behavior, which is useful, but says nothing about what 'validate' returns or how it signals failure, so some behavioral context is missing.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.