Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly, idempotent, non-destructive, closed-world, so the safety profile is covered. The description adds the genuinely useful behavioral fact that this returns an interactive rendered feed rather than data, but says nothing about how filters, limit, and opportunity_ids interact or which takes precedence.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.