Look up Norwegian company by organization number

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

With no annotations, the description carries full burden. It discloses the operation as a read ('Retrieves') and lists specific return fields (name, address, NACE codes, etc.), which is useful context. It does not mention error handling for invalid org numbers, but the scope is clear.

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: the first clearly states the function and output, the second provides usage guidance. No redundant wording, well-structured and front-loaded.

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 a single parameter and no output schema, the description provides a comprehensive list of return fields, the data source, and when to use it. It lacks explicit handling of invalid or missing org numbers or rate limits, but these are minor for a simple lookup tool.

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%, with the schema already describing 'orgnr' as a 9-digit Norwegian organization number with an example. The description adds no new parameter information beyond repeating the 9-digit format. Baseline 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?

The description clearly states the tool retrieves full details of a Norwegian business entity by its 9-digit organization number. The verb 'Retrieves' and specific resource (Brønnøysund Register Centre) distinguish it from sibling tools like search_companies (search) and get_company_roles (roles).

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?

Explicitly says 'Use this when the user provides or asks about a specific Norwegian orgnr.' This gives clear context for when to invoke the tool. It doesn't explicitly mention alternatives, but the sibling tool names imply search for vague queries, and the condition is precise.

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