Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description richly discloses behaviors beyond the annotation hints: variables are PUBLIC and REPLACE the entire set, secrets are SERVER-only, encrypted, never returned, and use patch semantics (empty string deletes, omitted unchanged). It also warns 'Never put a secret value in variables.' This is exemplary behavioral transparency.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.