Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden of behavioral disclosure. It only states that the tool lists users, which implies a read-only operation, but it does not disclose whether the list includes users inherited via groups, pagination behavior, authorization requirements, or any other behavioral details an agent might need.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.