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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds meaningful behavioral context beyond the schema: each page costs 1 credit, pagination has a max of 5 pages, and filtering is cheaper than paginating. It doesn't describe the response shape, but with no output schema and read-only annotations, the credit-cost disclosure is valuable context.

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 well-structured: a clear first sentence, a second sentence explaining purpose, a third routing sentence, and a cost-guidance paragraph. It is slightly longer than necessary, but every sentence earns its place—especially the credit-cost and pagination guidance, which is essential for safe cost-conscious invocation.

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 read-only list tool with 7 parameters and no output schema, the description covers what the tool returns, when to use it, and the cost model. It does not explicitly describe the response format, but given the output schema absence and the listing nature of the tool, the description is complete enough for correct invocation. Minor gap: it doesn't mention what happens when no seller offers exist or whether pagination is per-page sequential.

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 coverage is 100%, so the baseline is 3. The description adds semantic meaning by framing the credit cost per page and recommending filters instead of pagination, which directly informs how to set max_page and condition/shipping parameters. It also clarifies the domain principle ('use the domain that matches the user's market'), though that already appears in the schema. The description reinforces the filter behavior and page-cost tradeoff beyond the schema's raw field definitions.

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 ('Fetch the list of seller offers for an Amazon product') and enumerates exactly what data is returned: merchant price, shipping cost, condition, fulfillment type, seller rating, and Buy Box winner. It also explicitly distinguishes itself from get_product_detail, which is the sibling it could be confused with.

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?

Provides explicit when-to-use guidance ('when the question is about WHO sells the product and at WHAT price') and names the alternative (get_product_detail) with clear exclusion criteria. It also gives cost-conscious guidance on pagination and filtering, which is actionable and specific.

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