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

With no annotations at all, the description carries the full burden and does meaningful work: it discloses a per-call price ($0.01 USDC on Base, eip155:8453), the x402 payment mechanism and the exact param location (params._meta["x402/payment"]), the HTTP method and endpoint, and a 'no personal data' data-handling claim. It leaves gaps on rate limits, failure/empty-result behavior, and whether the sanctions hit is fuzzy or exact — hence not a 5.

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 dense but purposeful sentences, front-loaded with what the caller gets, then cost/payment, then transport. No filler and each clause maps to a decision the agent must make before calling.

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?

No output schema and no annotations, so the description must cover both shape and behavior; it does so by listing the returned fact categories and the payment precondition. It stops short of describing response structure, per-source failure handling, or result size, which matters for an aggregate dossier.

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?

Only one parameter, and the schema already documents it at 100% coverage, including the 'q' alias. The description adds no syntax, normalization, or matching-behavior detail (e.g. exact vs fuzzy name matching) beyond what the schema states, so this is the baseline 3.

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 names a specific resource (a joined company dossier) and enumerates exactly what it contains: SEC EDGAR identity/CIK/SIC/incorporation state, recent filings, RDAP domain facts, and an OFAC/UK/EU sanctions screen. That composition tells an agent precisely how this differs from narrower siblings like company_facts__lookup, edgar__company, domfacts__rdap, or check_sanctions__screen.

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?

Usage is only implied: the phrase 'One joined company dossier' signals this is the aggregate/one-shot alternative to the single-source siblings, but no explicit when-to-use or when-not-to-use guidance is given. An agent must infer that the $0.01 price and bundling make this preferable when multiple data facets are needed at once.

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