Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the tool's simplicity (1 parameter, read-only, non-destructive), the description is complete: it covers purpose, usage, behavioral traits (expiry), parameter semantics, and return values. With an output schema present, it doesn't need to detail return format further, and annotations handle safety aspects adequately.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.