Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden. It does disclose the single most important trait — all-or-nothing atomic execution — which is real value. However it says nothing about what happens when one command in the list fails, whether commands execute in array order, whether later commands see the effects of earlier ones, or whether a document must be open first.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.