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

Annotations already declare readOnlyHint and openWorldHint, and the description usefully adds that trackingTag is null until enrollment and that marketplace defaults deterministically by locale. It omits auth and failure behavior, but with annotations covering safety, this is substantive 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?

Three compact sentences front-load the core action and marketplace rule with no repetition. The OpenAPI alias is minor and does not weaken the structure.

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, the description identifies the main return value as buyUrl and notes trackingTag behavior. Marketplace defaulting removes the key ambiguity, though full return/error behavior is not documented.

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 75%, and the description adds meaningful marketplace semantics beyond the schema, including US/Sweden selection and default behavior. The remaining parameters are largely covered by schema descriptions and self-explanatory enums.

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?

States a specific verb and resource set: resolve ASIN, pasted Amazon URL, or keywords into a buyUrl. It is distinguishable from search_gifts and get_catalog, but it does not explicitly contrast itself with those siblings.

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?

Explains input forms and the marketplace-selection rule, including the en-US default. However, it does not say when to use this tool versus search_gifts or get_catalog, nor 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.