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

No annotations are provided, so the description must carry the behavioral burden. The description does disclose important behavioral nuances: it explicitly states that 'not found' is not interpreted as invalid or nonexistent, which is critical for correct use. However, it does not mention any other behavioral aspects such as rate limits, authentication, or what the response format is, which would be needed for a fully transparent behavior.

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 concise, two sentences long, and the key purpose is stated first. The not-found behavior is highlighted, which is important. The example is helpful but already present in the schema, so it is slightly redundant. Overall, it is well-structured and focused.

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 only one parameter and clear schema coverage, the description is mostly complete. However, it does not explain the expected output or return values, and for a verification tool, that could be important for an agent to interpret the result. It also does not mention any prerequisites or special conditions. The absence of output schema increases the need for description clarity, which is partially met.

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 a description for the single parameter and an example. The tool description also includes an input example. Since schema coverage is 100%, the description contributes minimal additional meaning, only the example which is also in the schema. Baseline 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 verifies qualified invoice issuer numbers (T+13 digits) for registration, cancellation, and revocation with dates. It also explicitly distinguishes the tool's behavior from sibling tools by stating that 'not found' is reported as 'personal not listed or not recorded' and not asserted as invalid or nonexistent. This is specific and sets it apart from corporate search 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?

The description explains what the tool does and how it handles not-found cases, but it does not explicitly state when to use this tool versus the siblings. Since siblings are corporate profile and search tools, the context is clear that this is for invoice number verification, but no alternative or exclusion is mentioned. The usage guidance is implied rather than explicit.

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