Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a simple, parameterless read-only tool, the description is largely sufficient: it states what is returned (latest retail price reading), the implicit output fields (source and date), and the intended context. It does not specify units or formatting, but with no output schema and a straightforward purpose, this is a minor gap rather than a blocking one.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.