Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a simple read-only listing tool with one optional parameter, the description is complete: it names the resource, scope, included fields, and exclusion. The output schema is absent, but the description enumerates the return fields sufficiently, and annotations cover behavioral safety.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.