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

No annotations exist, so the description carries the full burden, and it does well: it names the authoritative data source, discloses licensing (NLOD 2.0), and states a per-call cost of 0.01 USD via x402, which is critical pre-invocation context. It also lists the returned data categories (legal form, address, NACE, employees, VAT/register status, bankruptcy flags). It stops short of stating rate limits or failure behavior for a miss.

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?

Two sentences, front-loaded with what the tool does and its data source, followed by pricing/licence. The long enumeration of returned fields is dense but each item is informative; little is wasted.

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 usefully enumerates the returned attributes, and adds pricing and licensing that no structured field supplies. For a two-parameter read tool this is close to complete; only miss/failure behavior and rate limits are absent.

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 both parameters (name, orgnr) are already fully documented, including the 'up to 5 candidates' behavior for name search. The description's phrase 'by organisation number or name' restates the schema without adding format or precedence guidance. 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?

States a specific verb and resource – 'Norwegian company lookup in the official Brønnøysund Register Centre (Enhetsregisteret)' – with the lookup key (orgnr or name) and the field set returned. The country/register specificity implicitly separates it from dk_* and fi_company siblings, though no sibling is named outright.

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?

There is no statement of when to use this versus alternatives such as fi_company or lei_lookup, nor any prerequisites or exclusions. An agent must infer from the country qualifier that this is the Norwegian option, which is a reasonable inference but not explicit guidance.

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