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

Annotations already declare read-only, idempotent, non-destructive, and open-world behavior. The description adds meaningful behavior beyond them: normalized outcomes for no insolvency information, existing insolvency information, and lookup/source failure, plus the caveat that absence is not proof of financial health and the x402 price.

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-loads the purpose and stays compact without repeating schema details. The use-case sentence is somewhat generic and the pricing sentence is operational, but both are relevant; minor density keeps it from a 5.

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?

For a one-parameter read-only lookup with an output schema and rich annotations, the description covers purpose, result interpretation, use context, and a key inference caveat. The main omission is sibling differentiation from get_entity_insolvency.

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?

There is one parameter and schema description coverage is 100%; the schema already documents the company_number pattern, example, and source. The description's 'known UK company' aligns with that but adds no further syntax or format meaning, so the baseline of 3 is appropriate.

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 and resource ('Retrieve Companies House insolvency information') and scopes it to a known UK company, making it distinguishable from filings, officers, and profile tools. It does not explicitly distinguish itself from the sibling get_entity_insolvency, which keeps it below a 5.

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?

Gives clear usage contexts such as supplier checks, counterparty due diligence, and company-risk research, plus a caution about interpreting absence of data. It does not state when not to use it or name get_entity_insolvency as an alternative, so it lacks explicit exclusions and alternatives.

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