Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description complements the readOnlyHint annotation by explaining what kind of data is returned: current, baseline, and 30-day history based on likes and comments. It does not describe internal side effects or edge cases, but the annotation already covers the read-only safety profile.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.