Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly, idempotent, non-destructive, so the bar is lower, but the description still adds real interpretive context: the positive TechJobs estimate is from public sources, is explicitly not an official ranking, and a missing label means insufficient public data rather than a negative signal. That caveat prevents an agent from misreading absence as bad news; the only gap is no mention of error behavior for an invalid slug.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.