Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden, and it does disclose real behavioral traits beyond the schema: an invoice is issued for the full price, payment goes to the venue rather than the seller, funds are held in escrow until acceptance, and the seller receives 80%. It omits reversibility, auth requirements, and whether the order is immediately binding, so it is strong but incomplete.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.