Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden of behavioral disclosure. It reveals the data source ('Monaco markers'), which implies reading editor state, but doesn't say whether the operation is read-only, whether a prior compilation is required, or what happens when no markers exist. No side effects or failure modes are disclosed.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.