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

Annotations already establish readOnlyHint=true and openWorldHint=true. The description adds a meaningful behavioral detail beyond that: the returned buyUrl has trackingTag null until enrollment. It does not cover error cases or rate limits, but the added output-state context is useful.

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, front-loaded with the core action and immediately followed by the required-parameter rule and output note. Every sentence contributes useful information with no waste.

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 an 8-parameter, open-world read tool with no output schema, the description covers the essential call path: input types, required params, and the buyUrl return. It is incomplete on how the optional occasion, budgetBand, and giftCategory parameters influence resolution, and it offers no failure or rate-limit context.

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 moderate (63%). The description restates the main documented inputs (ASIN, URL, keywords, marketplace, locale) and reinforces the two required fields, but it says nothing about occasion, budgetBand, or giftCategory, which are undocumented in the schema as well. It adds some clarity but does not compensate for the coverage gap.

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 a specific verb (resolve) plus the three accepted input modes (ASIN, pasted Amazon /dp/ URL, keywords) and the output (buyUrl). That is clear, but it does not explicitly differentiate this from siblings like search_gifts, which could also consume keywords; an agent has to infer the boundary.

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 a clear prerequisite: 'ALWAYS pass marketplace + locale,' and the purpose sentence makes the general use case obvious. However, it never states when to prefer this over search_gifts or when not to use it, so it stops short of full alternative routing.

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