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

Beyond the readOnlyHint and openWorldHint annotations, it discloses the paid x402 behavior, exact cost, what happens without payment, and how to retry with the required headers or params._meta. This is critical operational context the annotations do not provide.

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?

Three tightly written sentences: purpose first, scope exclusion second, payment mechanics last. Every sentence carries necessary information with no filler.

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?

The description covers purpose, scope, and the unusually important payment behavior. It does not describe the shape of the QA result, and since there is no output schema, that is a minor gap, but the tool remains understandable and callable.

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 100% and the single listing object already enumerates titleEn/titleZh/descriptionEn/descriptionZh/bulletPoints/price/currency. The description adds the check categories but no additional syntax or constraints beyond the schema, so baseline 3 is appropriate.

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 names a specific verb and resource: heuristic QA for caller-supplied EN/zh product listing fields, with examples of checks (length, CJK/Latin mix, promo noise). It also explicitly excludes translation, which is the most likely mistaken interpretation.

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?

It clearly establishes the use case: QA on caller-owned listing fields, not translation. It does not explicitly name sibling alternatives such as product_title_normalize or seo_audit, but the intended context is clear.

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