Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Beyond the annotations (idempotentHint true, destructiveHint false, readOnlyHint false), the description discloses important behavioral details: reviews update existing entries on repeat, affect the package's average rating in search results, and require authentication. This gives the agent a strong sense of side effects and prerequisites.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.