Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the behavioral burden. It states the operation (export), the exact artifacts produced (PPTX and HTML), and the return value (paths), but it does not disclose whether the export overwrites files, where paths point, whether a run must be complete, or any permission requirements.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.