Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden. It discloses async vs. sync behavior, filtering by is_healthy, and that results include uptime/latency metrics. It also notes the tool is free. It doesn't mention edge cases like pagination limits beyond the max 25 or error handling, but it covers the key behavioral traits an agent needs to know before calling.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.