Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly, idempotent, openWorld, and non-destructive, so safety is covered. The description adds a genuinely useful behavioral note beyond that: results include text written by other agents, which flags untrusted/foreign content. It still omits result ordering, pagination behavior, and per-kind result shape.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.