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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It states the data source (Companies House UK) but does not describe what the response contains, pagination behavior, or any potential limits or quirks. For a search tool, the agent would benefit from knowing the result format (e.g., list of officers with names and dates of birth). The description is too sparse to provide meaningful 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 two concise sentences. The first sentence front-loads the main action and resource, and the second provides useful context about source and use case. Every word earns its place, with no fluff or repetition.

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?

This is a simple search tool with two parameters and no output schema. The description conveys what the tool does, its source, and a use case. However, it could be more complete by explicitly stating that the output is a list of matching officers, since there is no output schema. Given the low complexity, the current description is nearly sufficient, earning a 4.

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 adds no additional parameter meaning beyond what the schema already provides: 'by name' matches the 'q' parameter, and the schema already describes 'limit' with its default. Since the schema is fully descriptive, the description does not need to compensate.

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: 'Search UK company officers (directors) by name.' This is a specific verb+resource+scope. It also distinguishes from siblings by specifying 'by name', which differentiates it from uk_company_officers (likely company-specific) and uk_company_search (company search). The mention of 'Best for director background checks' further clarifies its intended use.

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 for when to use this tool: 'Best for director background checks.' It does not explicitly name alternative tools or say when not to use them, but the context is clear. Given the sibling set includes other UK officer tools, a more explicit exclusion would earn a 5, but the use case guidance is sufficient for a 4.

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