Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given a tool with 1 undocumented parameter, no annotations, no output schema, and five similar sibling tools, the description is completely inadequate. It provides no meaningful context about what the tool does, how to use it, what parameters mean, or how it differs from alternatives. This leaves the agent unable to make informed decisions about tool selection and invocation.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.