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

The description states 'no external research or outbound actions', which directly contradicts the openWorldHint=true annotation (which indicates the tool may return information beyond inputs). Additionally, destructiveHint=true is not explained by the description, but it does mention payment requires explicit wallet authorization. The contradiction with openWorldHint is a serious inconsistency, so a score of 1 is warranted.

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 concise, two sentences, and front-loads the core purpose. It includes necessary caveats about pricing and payment. However, it omits parameter details, which might be considered a completeness issue but not a conciseness issue. The structure is efficient 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?

Given the nested object schema, five parameters, and no output schema, the description is incomplete. It does not explain the purpose of idempotency_key, result_signature, payment_signature, or result_expires. It only vaguely mentions a draft for review. The contradiction with openWorldHint further undermines completeness. More detail on parameters and expected output is needed for an agent to use it correctly.

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 0%, so the description must compensate. It does not explain any of the parameters such as 'brief', 'source_text', 'audience', or the various signatures. The description mentions 'supplied keywords' but does not map them to any specific field. With three nested parameters and no description, the agent cannot infer parameter meanings from the description or schema.

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 and resource: 'Group supplied keywords by intent and topic'. It also adds a distinguishing detail: 'explain ambiguous groupings' and 'do not invent search volume', which differentiates it from siblings like search_intent or keyword_page_map. The mention of returning a draft for human review further clarifies its role.

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 context on when to use: 'Uses buyer-supplied information only; no external research or outbound actions' and notes payment authorization. However, it does not explicitly mention alternatives or when not to use this tool versus siblings such as search_intent or keyword_page_map. It gives a clear context but lacks exclusions.

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