Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Without annotations, the description carries the burden of disclosing behavior. It states the tool searches the web, fetches sources, and 'answers strictly from them,' which indicates a read-only, source-grounded behavior. It also discloses the cost ('Price: $0.05'), a key side effect. It does not mention rate limits or edge cases, but for a simple question-answering tool, this 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.