Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The annotations only provide openWorldHint=true, so the description carries the behavioral burden, and it delivers: states that the platform will reject running builds (not an error but protection), and warns that retrying code-failures will produce the same result. It doesn't mention the return format, but the output schema exists to cover that.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.