Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare it read-only/idempotent, but the description goes well beyond them: it discloses that no message is actually sent (the key behavioral surprise), imposes a PII constraint, and details data retention (12 months), what is logged (messages, time, app, approximate location), and that no IPs are stored. This is unusually rich behavioral context.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.