Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the burden of behavioral disclosure. It does disclose the key safety property that the import is idempotent and repeatable, which is valuable. However, it does not state whether existing calendar data is overwritten, merged, or preserved, nor what side effects or return signals the call produces.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.