Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds the useful qualifier that content comes from a 'public feed' and is 'fresh', implying no auth and recency-ordered results, but says nothing about volume, pagination, or update cadence.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.