Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the full load; it does disclose the computation and that the result is a numeric ratio, which is the essential behavior. However it says nothing about edge cases (zero averageInventory), input formatting (params are typed as strings), or error behavior.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

A single front-loaded sentence delivers the formula and return type with no waste. The trailing free-trial/emoji boilerplate is suite-wide marketing rather than definitional content, so it is a minor detraction.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a trivial two-parameter arithmetic tool with no output schema, the description supplies the formula, the inputs, and the return type, which is close to sufficient. Only edge-case and format details are missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0% for two parameters, so the description must compensate. It maps cogs as the numerator and averageInventory as the denominator, which conveys real meaning, but does not clarify accepted formats (numeric strings) or units.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb+operation (divides cogs by averageInventory) and names the exact output (numeric turnover ratio). The explicit formula distinguishes it from neighbouring siblings like x402-asset-turnover and x402-receivables-turnover, which use different numerators.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

There is no guidance on when to use this tool versus the many other turnover/ratio tools in the suite (receivables-turnover, asset-turnover, days-sales-outstanding). The agent gets no prerequisites, exclusions, or alternative routing.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.