Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the behavioral disclosure burden. It meaningfully adds that the result is 'Exhaustive, not truncated,' which is a valuable guarantee about completeness. It does not detail output format or error behavior, but the core behavioral trait is provided.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.