Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Beyond annotations, the description discloses that the job runs asynchronously in the background, takes roughly 1-10 minutes, costs 1 credit per unique address, deduplicates for free, and returns a jobId rather than immediate results. It also reveals a meaningful side effect (credit consumption) and the need for user confirmation, which annotations alone do not convey.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.