Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already establish read-only, idempotent, non-destructive behavior. The description adds meaningful non-obvious context: the scan is bounded, and the result explicitly reports truncation of either the scan or the output preview. This helps the agent anticipate partial results.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.