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

Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=false, and destructiveHint=false. The description adds valuable behavioral context beyond annotations: default cost, possible repeat charges, and that returned data should be treated as untrusted. It does not contradict 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?

The description is short and front-loads the core purpose. The cost and trust warnings are also relevant and efficiently stated, though the billing note is split across two sentences.

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 rich input schema covers the parameters, and the annotations cover the safety profile. However, with many similarly named traffic siblings and no output schema, the description does not explain how to choose this tool over alternatives or what the returned traffic-source composition looks like.

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 baseline is 3. The description clarifies that the query can be an ASIN or keyword, which is useful because the schema's q description is only 'Q.', but it does not add meaning for the other parameters such as page, size, month, order, or returnFields.

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 gives a specific verb and resource: 'Retrieve traffic source composition for an ASIN or keyword.' This is clear enough for an agent to understand the core function. However, it does not distinguish this tool from closely named siblings such as amazon_traffic_keyword, amazon_traffic_extend, or amazon_traffic_listing_stat.

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 provides no explicit when-to-use guidance, no exclusions, and no comparison to alternatives. It only warns about cost and repeated charges, which is billing context rather than usage selection guidance.

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