Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a simple read-only list tool with one parameter, the description covers the essential elements: purpose, ordering, permission, and next steps. There is no output schema, but the concept of 'version history' implies a list of versions. A slightly richer description of the return values (e.g., containing timestamps or version numbers) would make it a 5, but it is complete enough for confident invocation.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.