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

With no annotations, the description carries the full burden of disclosing behavior. It states 'Returns full company details,' which indicates the nature of the output, but it does not disclose potential error behavior (e.g., what happens if the CVR number is not found), whether the operation is read-only, or that the `country` parameter can return Norwegian data. The description provides only a minimal behavioral snapshot.

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 a single sentence of 15 words, front-loaded with the verb 'Look up' and the resource. It contains no filler and every word serves a purpose. This is appropriately concise.

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?

Given the tool's low complexity (2 params, no output schema), the description is adequate but has gaps. It does not explain what 'full company details' includes, nor does it mention the `country` parameter or provide guidance on using `cvr_search` as an alternative. Since there is no output schema, the description should provide more detail about the return value and potential edge cases.

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 the baseline is 3. The description itself adds no extra meaning to the parameters; it only mentions '8-digit CVR number,' which is already in the schema's description. It does not clarify the `country` parameter's role, and the description's focus on 'Danish' could even conflict with the country enum. Thus the description adds no value beyond the schema.

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's function: 'Look up a specific Danish company by its 8-digit CVR number. Returns full company details.' It uses a specific verb and resource, and distinguishes from the sibling `cvr_search` by focusing on exact-number lookup. However, the description is slightly misleading because the schema allows a `country` parameter with values 'dk' or 'no', yet the description only mentions Danish companies, which conflicts with that broader scope.

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?

The description implies when to use this tool: when you have a specific 8-digit CVR number. It says 'Look up a specific... by its 8-digit CVR number,' which gives clear context for when to use this tool over a search tool. However, it does not explicitly mention the sibling `cvr_search` or explain when to prefer one over the other, so it lacks explicit exclusion/alternative guidance.

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

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

With no annotations provided, the description carries the burden of behavioral disclosure. It adds meaningful context by detailing the return fields (address, industry, employees, owners, status) and the country scope (Denmark/Norway). While it doesn't address rate limits or error behavior, it gives a solid picture of what the tool does and returns.

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 three concise, front-loaded sentences. The first sentence states the primary action and supported search keys, the second lists return content, and the third adds the Norwegian scope. Every sentence contributes useful information with no redundancy or fluff.

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?

The tool has no output schema, and the description does not clarify whether it returns a single company object or a list of matches, which is important for a search tool. The input schema is well-covered, and the return fields are listed, but the result shape ambiguity leaves an avoidable gap in understanding.

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%, so all parameters are already documented. The description adds no significant new parameter-level detail beyond what the schema provides; it merely restates that searches can be done by name, CVR, P-number, or phone, which matches the search_type enum. 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?

The description clearly states the tool searches the Danish CVR registry by name, CVR number, P-number, or phone and returns company details. It uses a specific verb and resource, making the purpose unmistakable. However, it does not explicitly distinguish this from the sibling tool cvr_lookup, so it stops short of a perfect score.

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?

The description provides clear context on what kinds of searches are supported (name, CVR, P-number, phone) and that Norwegian companies are also searchable with country=no. It does not explicitly say when to use this tool instead of cvr_lookup or when not to use it, but the intended usage is well implied.

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