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

Annotations already cover the safety profile (readOnlyHint, openWorldHint), and the description adds genuinely useful context: the $0.02 USDC per-call x402 payment requirement and the return shape (0-100 score, level, flags). It does not mention data freshness or rate limits, but the cost/payment disclosure is significant added value.

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?

Front-loaded with the purpose, then the checks, then return shape and cost. Every clause is a distinct signal; no filler or repetition of the title.

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?

With no output schema, the description correctly explains the return values (risk score, level, flags) and the payment model. For a complex multi-signal tool it is nearly complete, but it omits how to identify the company (name vs number) and any data-freshness note.

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?

The description never mentions the two parameters at all. The schema documents only 'number' ('Company number'); 'name' is undocumented, and with 0 required parameters the description gives no clue whether a company name or number is needed to call it.

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?

States a specific verb, resource and scope: 'UK business verification (KYB) risk check in one call'. The enumerated checks (status, insolvency, PSC, disqualified directors) clearly differentiate it from siblings like uk_company, uk_disqualified and uk_filings.

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?

'in one call' implies this aggregates the checks that siblings such as uk_company/uk_disqualified/uk_filings would require separately, which is soft routing guidance. There is no explicit when-to-use/when-not statement or named alternative, so usage is only implied.

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