Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a simple tool with one parameter, no output schema, and annotations covering destructive and idempotent aspects, the description is largely complete. It explains purpose, usage, and relationship to siblings. It could mention success/failure or error handling for missing keys, but the current level is adequate given the tool's simplicity.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.