Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full behavioral burden, and it does disclose two useful traits: no network calls and a cost of 1 credit per call. However, it omits failure behavior for malformed input, output format, and the 1,000,000-char input limit, which matters for a mutation-free but size-constrained tool.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.