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

Annotations already declare this as read-only, idempotent, and non-destructive, so the safety profile is covered. The description adds that it returns ASINs and titles, and includes an example call. However, it doesn't discuss potential rate limits, result limits, or error handling. Since annotations cover the main behavioral aspects, the description adds moderate value but not extensive detail.

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 extremely concise: one sentence stating purpose, then an example call. No wasted words, and the core function is front-loaded. It follows the ideal structure for a simple tool: what it does, plus a concrete invocation example.

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 simple search tool with only three parameters and no output schema, the description gives the essential information: it searches and returns ASINs. It does not mention pagination, result limits, or how many items are returned, which could be important for agents. However, given the tool's simplicity and the annotations covering safety, it is mostly complete but leaves some operational details unaddressed.

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?

The schema provides 100% coverage of all three parameters with descriptions, so the baseline is 3. The description reinforces usage via an example showing term, domain, and _apiKey together, but does not add new meaning beyond the schema. The domain parameter's default and reference to keepa_product for the full list is already in the schema. The example is helpful but not transformative.

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 clearly states the tool's function: searching Amazon for a keyword and returning ASINs. It uses a specific verb ('Search') and resource ('Amazon'), and specifies the output (ASINs and titles). It does not explicitly differentiate from sibling tools like keepa_bestsellers or keepa_deals, but the purpose is unambiguous enough that an agent can infer it is the keyword-search option. Minor deduction for lacking a direct sibling comparison.

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?

There is no guidance on when to use this tool versus alternatives. The description doesn't mention when it's appropriate, when not, or point to other Keepa tools like keepa_product for fetching details or keepa_bestsellers for rankings. An agent must infer usage from the name and description alone, which is a significant gap.

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