companies_house_company_profile

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

No annotations are provided, so the description must disclose behavioral traits. It only states the API key requirement, omitting details such as read-only nature, rate limits, error handling, or data scope. This is insufficient for full behavioral transparency.

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 that front-loads the purpose and includes a key requirement. It is concise and to the point, but could be slightly better structured with a separate line for the requirement.

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 has an output schema and one required parameter, the description still lacks completeness. It does not explain what data the profile contains, any constraints on the company number (e.g., UK companies only), or the nature of the operation (read-only). The API key requirement is stated but not elaborated.

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?

The input schema has a single parameter 'company_number' with no description (0% schema description coverage). The tool description provides no additional meaning about the parameter, such as format or source, leaving the agent with no guidance on what value to provide.

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 verb 'Fetch' and resource 'Companies House company profile', making the purpose obvious. However, it does not differentiate from sibling tools, which include various data fetch operations, so it is clear but not distinctive.

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 mentions the requirement of COMPANIES_HOUSE_API_KEY, which is a usage precondition. It does not provide guidance on when to use this tool versus alternatives, but since no other Companies House tool exists among siblings, usage is implied. Score 3 for implied usage with a key requirement.

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