Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already establish read-only, idempotent, open-world behavior. The description adds useful operational context: the data is pre-scraped and costs $0.001 USDC. However, it does not disclose other behavioral traits such as response caching, rate limits, or what happens on payment failure.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.