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

Annotations already cover safety (readOnlyHint, destructiveHint=false) and the non-idempotent nature, but the description adds genuinely useful operational context beyond them: credit cost per successful call, plan-dependent actual cost, and re-charging on repeated calls. The untrusted-data warning is a valuable security note that annotations cannot convey.

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 short sentences, purpose front-loaded, no filler or repetition of the tool title. It is efficiently sized, though the brevity leaves useful usage context out rather than being maximally informative.

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 10-parameter tool with a nested sort object and no output schema, the description is thin: it never characterizes the response payload, pagination behavior, or which reverseType/conversionType values mean. The schema carries the parameter burden well, but the missing return-shape context leaves a real gap.

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%, so the schema already documents date formats, page/size limits, marketplace enums, ASIN constraints, and the nested sort object. The description adds no parameter-level meaning (e.g., what reverseType W vs M means beyond the schema), so the baseline 3 applies.

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?

Names a specific verb (Retrieve) plus the exact resource (keywords that generate orders for ASINs), which is more precise than a generic 'keyword lookup'. However, it does nothing to distinguish itself from sibling keyword tools such as amazon_keyword_conversion, amazon_keyword_research, or amazon_traffic_keyword, so selection among siblings still requires schema inspection.

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 contains no when-to-use or when-not-to-use guidance and never names an alternative tool. The only conditional statements are about billing, not about selecting this tool over its many keyword siblings.

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