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

Annotations cover safety (readOnly, idempotent, openWorld), and the description adds substantial context beyond them: price and settlement currency, the coverage block naming registers NOT consulted, the never-guess policy for unread registers, the four possible verdicts, and an offline-verifiable Ed25519 receipt with a published key URL. This is exactly the kind of operational detail an agent needs before invoking a paid tool.

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 core claim is front-loaded, but the single enormous sentence with stacked em-dashes is hard to parse and carries marketing padding ('the whole picture', 'never guessed'). Pricing and audit-receipt details earn their place; the rhetorical framing does not.

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 it does: verdict states, the coverage block, and the signed receipt. Combined with annotations covering the read-only/idempotent profile, an agent has everything needed to call and interpret this 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 coverage is 100%, and the schema already documents both 'query' (company number, legal name, LEI or CIK) and 'jurisdiction' with examples. The description adds little parameter-level detail, notably nothing about how jurisdiction breaks ties, so the baseline 3 applies.

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 concrete deliverable: a single paid answer consolidating identity/standing, registered office, SIC activity, previous names, filing position, sanctions screening and ownership for one company. That clearly separates it from narrower siblings like check_sanctions or check_figure. It never names an actual sibling tool, though, so the differentiation is inferred from the field list rather than stated.

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 usable when-to-use context: 'at the point of signing, onboarding, paying or acquiring a counterparty,' and an explicit exclusion, 'Not advice, not a credit check.' What is missing is routing guidance to sibling alternatives (e.g. when to use check_entity or check_sanctions instead of paying for the full file).

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