Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden of behavioral disclosure. It reveals that the randomness comes from a CSPRNG, is attested, and is signed, plus the exact return format. It doesn't mention potential error conditions or rate limits, but for a simple tool this is reasonable. It adds useful context beyond just 'returns a random number'.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.