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

The description states 'no external research or outbound actions,' but the annotations set openWorldHint=true, which indicates the tool may interact with external systems. This is a direct contradiction. While the description does disclose pricing, payment authorization, and the draft-for-review nature, the contradiction with annotations makes this score a 1.

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 three sentences, front-loaded with the primary purpose, and includes essential operational details (pricing, payment, no external actions). There is no fluff; every sentence earns its place.

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 tool has 5 parameters, nested objects, no output schema, and contradictory annotations. The description covers the core extraction behavior and payment requirement but leaves many parameters unexplained and does not describe the return structure beyond 'clearly structured artifact.' An agent would lack critical information to invoke the tool correctly, especially regarding signatures and expiration.

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 gives some context: 'brief' likely specifies requested fields and 'source_text' is the text, but it does not explain audience, result_expires, idempotency_key, result_signature, or payment_signature. With zero schema descriptions, these parameters remain ambiguous, and the description adds minimal value beyond the core inputs.

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 a specific verb (extract), resource (supplied text), and output (structured artifact). It also specifies the null-for-missing-data behavior and distinguishes itself from external-research tools by stating it uses buyer-supplied information only. This is easily differentiable from siblings like entity_extraction or text_classification.

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 implies usage context: it is for extracting requested fields from supplied text without external research. However, it does not explicitly name alternative tools or state when not to use this tool. It gives a clear scope but no exclusions or sibling comparisons, so guidance is implied rather than explicit.

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