Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations present, the description carries the full burden. It correctly implies a read-only operation ('list all') and adds context about workspace scoping. It does not contradict the lack of annotations, and for a simple list tool with no parameters, it is sufficiently transparent about behavior.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.