Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the burden, and it clearly discloses what the tool produces: every field's key, label, type, required flag, help text, and allowed options. It also conveys the relationship to submit_enquiry. It does not mention return formatting or edge cases, but for a no-parameter, read-only schema tool the disclosed behavior is adequate.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.