Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description must carry the behavioral burden. 'Get' conveys a read-only operation, but the description does not disclose what information is returned, whether it requires a live connection, or whether any data is cached. For a zero-parameter read-only tool this is a modest but not severe gap.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.