Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly, openWorld, idempotent, and non-destructive behavior, so the description need not repeat that. The description adds useful behavioral context: results are Schema.org-typed, mode 'summarize' adds an extractive summary, and itemType narrows the corpus. No contradictions with annotations.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.