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

Annotations already establish read-only, idempotent, non-destructive semantics, so the description is free to add what they cannot: the specific price ($0.0104 USDC), the payment rail (x402 on Base mainnet), and the billing-safety guarantee that unsupported calls are rejected before payment. Jurisdiction-dependent variation in role semantics is also disclosed, which prevents the agent from assuming uniform output across entities.

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 front-loaded sentences covering capability, jurisdictional scope, and commercial terms, with no filler. Slight deduction because 'normalized authoritative' is dense abstraction that conveys little concrete meaning to a selecting agent, and the pricing sentence, while useful, is appended as a flat trailer.

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 an output schema present, the description need not explain return shape, and it covers the two things structured fields cannot: geographic coverage limits and cost/payment behavior. The remaining gap is that it never states what happens for entities outside GB beyond a generic rejection, nor whether a prior search_company call in the same session is required.

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 only one parameter and schema coverage is 100%, with the schema itself explaining that entity_id is a stable ID from search_company to be passed unchanged. The description reinforces the 'resolved legal entity' precondition but adds no format, length, or validation detail beyond what the schema already states, 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 specific verb ('Retrieve') and a specific resource ('normalized authoritative management or registered-role information') scoped to a 'resolved legal entity'. The word 'resolved' implicitly separates it from the name-search paths used by siblings like get_company_officers, but no sibling is named outright, so the differentiation is inferred 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 clear positive context (GB coverage today, jurisdiction-dependent role semantics) and a negative condition (unsupported capabilities are rejected before payment), which is exactly the kind of when-not guidance an agent needs. It stops short of an explicit 5 because no alternative tool is named for cases where registry coverage does not exist or the caller only has a company name.

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