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

With no annotations, the description must convey behavioral traits. It implies a read-only operation through 'look up' and lists the returned data types, which is helpful. However, it does not disclose possible nuances like multiple results, error behavior, or the fact that the company parameter may be optional, leaving some behavioral ambiguity.

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, front-loaded sentence that conveys the essential purpose and output fields without unnecessary words. Every element earns its place, making it highly concise and well-structured.

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 simple two-parameter lookup tool with fully documented schema, the description adequately covers the purpose and expected return fields. The main gap is that it does not clarify the optionality of the company parameter or the return format, but the task is simple enough that the description is mostly complete.

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 already provides detailed descriptions and examples for both parameters (company and country), achieving 100% coverage. The tool description adds no extra parameter-specific semantics, so the baseline score 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 looks up company details and enumerates the specific fields returned (registration, status, address, incorporation date). The verb 'look up' and resource 'company details' distinguish it from sibling tools that handle domains, emails, people, or startups.

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 use when needing company details, but it does not explicitly state when to use this tool versus alternatives or mention any exclusions. The sibling tool names suggest related lookup tools, but the description offers no direct comparison or alternative guidance.

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