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 genuinely useful behavior: cost ($0.05 per call) and the payment mechanism (x402, USDC on Base), which an agent must know before invoking. It says nothing about pagination, result caps, or rate limits, so the transparency is partial rather than rich.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.