Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full behavioral burden. 'List files' implies a read-only operation, but the description does not disclose response shape, authentication requirements, rate limits, or whether the result is a bare file list or includes metadata. The minimal wording is not misleading but is under-transparent.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.