Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are supplied, so the description carries the full burden, yet it only discloses two returned fields. It says nothing about ordering, pagination, whether listing is recursive, whether all files or only shared ones are included, or any permission requirements — all relevant for a zero-argument tool that enumerates remote state.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.