Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds behavioral context beyond annotations by revealing the output format (CSV) and that it is for download, plus the expectation that input comes from a prior search/query. This is useful but does not dive into edge cases.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.