Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries full burden of behavioral disclosure. It only says 'generate random integer(s)' and omits key traits: it can generate multiple numbers, respects inclusive range, and defaults. The schema fills some gaps, but description should summarize.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.