Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden. It discloses the content returned (source, date, licence, citation) and the purpose, but doesn't specify the format (e.g., text, structured fields) or any side effects. For a read-only metadata tool, this is sufficient transparency, though it could mention that it returns a summary or text block.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.