Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover readOnly/openWorld/non-destructive, and the description adds genuinely new behavioral context: only metadata (title, link, date, section) is returned, with no article body or AI summary, and full text lives only at item.url. It doesn't discuss result ordering or rate limits, but the return-shape disclosure is the important part.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.