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

Annotations only declare readOnlyHint and openWorldHint; the description adds substantial behavior the annotations cannot express: 30-90 s latency, the async/webhook escape hatch, the confirm-company-first rule ('otherwise no job and no charge'), the no-charge rule when too few sources respond, and the $5 USDC x402 price. This is exactly the operational context an agent needs before spending money and time.

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?

It is a single dense block, but it is well front-loaded: deliverables first, then latency/async mechanics, then eligibility exclusions, then price. Almost every clause carries information, though the 14-source enumeration is long enough to risk burying the constraints.

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?

There is no output schema, so the description carries the return-value burden and does so fully: it names the narrative overview, 0-100 risk score, red flags, positives, cited key facts and the 7-day PDF link. Cost, timing, async path and eligibility are all covered, leaving nothing an agent must guess.

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 100%, so the baseline is 3, but the description genuinely adds meaning beyond the schema strings by tying async to 'job id at once' with the 30-90 s synchronous latency, and by pairing webhook_url with async. pdf default and the identifier parameters are left entirely to the 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 opens with a specific verb+resource ('Full company background report in one call') and then enumerates exactly what the report contains across 14 sources, which lets an agent separate it from narrow siblings like company_registry, uk_company or uk_kyb. An agent knows precisely what it gets before opening the schema.

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?

Strong conditional guidance for the async path ('add async=true and webhook_url to get a job id at once') plus explicit exclusions ('Companies only, not individuals; not a credit check or sanctions screening') and cost. It does not, however, state when to prefer this over sibling tools such as company or report_competitors, 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.