Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations exist, so the description carries the burden. It conveys a read-only intent ('details of a single order') and discloses the returned fields (status, filed size, avg price, fee), which is helpful. It doesn't address error behavior, neither what happens for a nonexistentId id, but for a state read it explains the core behavior the agent needs. Placing a baseline 3 given zero annotation coverage. This adds some value beyond trivially implying 'get'.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.