Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden. It states the tool retrieves order book data from the chart, indicating it is a read-only operation tied to the chart's context. It does not detail the return structure or number of levels, but for a simple getter this is adequate.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.