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

Annotations already declare readOnly/idempotent/non-destructive, and the description adds the credit-cost difference, the accepted retailer set, and the exact response fields since there is no output schema. It does not cover errors or pagination limits, but what it adds is materially useful beyond the annotations.

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?

It is compact and front-loads the resource and output, then gives call guidance and a warning. The example is somewhat redundant with the schema and context, but it is short and does not meaningfully hurt readability.

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?

With no output schema, it compensates by listing returned fields, and it covers input alternatives, pagination, retailer scope, and cost. It omits minor edge details like error behavior or country_code usage, but those are already documented in the schema.

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 the relationship between url, id, and asin ('url (or Amazon id/asin)'), recommends url, and gives a concrete example with retailer and page. This is extra semantic value beyond the property descriptions.

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 states the resource ('reviews for a product on a retailer') and lists the returned fields, so an agent can tell it fetches review data rather than product/search data. It does not explicitly name sibling tools like unwrangle_product or unwrangle_search, relying on the noun 'reviews' and the retailer list for differentiation.

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 gives clear call conditions: pass a product url (or Amazon id/asin) and optional page, and warns that reviews cost more credits than product/search. This implies the trade-off against cheaper alternatives, though it never explicitly says 'use unwrangle_product/unwrangle_search for non-review data' or states when not to use it.

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