Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
The tool is simple with one optional parameter and no output schema, so the description carries the responsibility for explaining return values. It says 'crypto headlines' but does not specify the structure (e.g., list of objects with titles, URLs). However, given the simplicity and the clear cache/filtering notes, the description is largely sufficient, leaving only a minor gap around output formatting.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.