Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Beyond the readOnly/openWorld annotations, the description discloses concrete operational behavior: the paid cost ($0.002 USDC), accepted payment rails (x402 on Base, Solana, or Arc), and the fact that failed calls are not charged. It also bounds the dataset to the public page's top 1–50, which clarifies scope without contradicting annotations.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.