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

Annotations already mark it read-only and non-destructive. The description adds meaningful behavioral detail: the sales and revenue figures are estimates weighted by buy-box share, buybox share is normalized rather than raw observed days, and est_sales is the default sort. These clarifications prevent misinterpretation of returned metrics.

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?

The description is front-loaded with the core behavior, then return metrics, sorting options, use-case triggers, and additional returned fields. Every sentence carries information needed for selection or invocation, and the trigger list, though somewhat long, is purposeful for agent matching.

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?

Because there is no output schema, the description compensates by explaining return fields and metric semantics. The annotations cover the safety profile, and the core call path — operator_name plus optional sort/limit — is clear. It does not document every optional filter, but it is complete enough for correct selection and basic invocation.

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?

Sentence says schema coverage is only 30%, so the description must compensate. It adds useful semantics for sort values, est_units_30d, est_revenue_30d, and buybox share, but the remaining 33-parameter surface — date windows, min/max thresholds, fulfillment percentages, and contains filters — is largely left to self-explanatory parameter names. That is partial, not complete, compensation.

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?

The description opens with a specific verb and resource: 'Show the ASINs an operator wins the buybox on most often,' and states the default ranking by estimated 30-day sales. It also frames the tool as an 'ASIN-level operator drill-down,' which distinguishes it from sibling tools like operator_top_brands and operator_category_dominance.

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?

The description explicitly gives trigger phrasing such as 'what ASINs does this seller win on', 'top ASINs for operator X', and 'any ASIN-level operator drill-down,' so an agent knows when to select it. It does not name sibling alternatives or state when not to use it, so it stops short of a perfect 5.

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