Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description must carry the behavioral burden, and it does disclose the content scope of what comes back. It does not state that the operation is read-only, whether results are truncated or how "recent" activity is bounded, nor anything about size or ordering. Useful content disclosure, but gaps remain.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.