Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false, covering the safety profile. The description adds valuable behavioral context beyond these: it discloses the fuzzy-match suggestion behavior on miss, and it describes the nature of the returned data (identity, raw signals, sub-scores, evidence-ready status). This is exactly the kind of context that helps an agent anticipate results. No contradiction.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.