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

Annotations already establish read-only, non-destructive, open-world behavior. The description adds valuable operational context beyond the annotations: the 100 company-relation cap, the Starter plan requirement, and how legal-owner holdings appear as a LEGAL EJER role with ejerandel.

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?

The description is compact and front-loaded: it identifies the resource, the required identifier, the returned relationship scope, and the main limitations within three efficient sentences.

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 tool with no output schema, the description gives enough to call it correctly and understand the main result. It does not explain pagination or behavior beyond the 100-relation cap, but otherwise covers purpose, identifier source, scope, and plan requirement.

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 already 100%, so the schema documents the single id parameter. The description still adds meaning by clarifying that the id is an enhedsnummer, is CVR's person number, must come from search_persons, and is never a CPR number.

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 states a specific verb and resource: retrieving one person by unit number along with the companies they own, direct, or board. It clearly distinguishes this person-centric lookup from sibling tools such as search_persons and the company-centric ownership tools.

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 tells the agent to use this tool to map a person's business network and that the id comes from search_persons, never a CPR number. It does not explicitly exclude edge cases or name alternative tools for similar network queries, but the intended context is clear.

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