Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
With one required parameter, full schema coverage, and no output schema, the description does the remaining work by enumerating the returned fields (revenue, net income, EPS, assets, equity) and the data source. Only minor gaps remain, such as units/currency or behavior when fewer than 5 or invalid tickers are supplied.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.