PESEL/NIP/REGON Validator

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

No annotations are provided, so the description must carry the full burden of behavioral disclosure. It fully reveals the checksum algorithm and input format constraints, but stops short of stating whether the tool throws exceptions or returns a boolean, which would be ideal for a validation tool.

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?

Three concise sentences, each earning its place: purpose, algorithm, and an edge-case. No superfluous words.

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 simple tool (1 parameter, no nested objects, single purpose) and the presence of an output schema (which would document return type), the description is complete and leaves minimal ambiguity for the agent.

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% with one well-described parameter. The description adds value by specifying 'digits-only' and 'no spaces or dashes' beyond the schema, but baseline is 3 per guidelines since schema already covers the parameter well.

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?

Uses specific verb 'validates' and resource '10-digit Polish tax identification number (NIP)', clearly distinguishing it from sibling tools like pesel_validate and regon_validate.

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?

Description explicitly covers when to use (validating a NIP), and sibling tools provide context for alternatives (PESEL, REGON). The algorithm details help the agent reason about correctness.

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?

No annotations exist, so the description carries the full burden. It discloses the checksum algorithm, date-of-birth and sex decoding on success, and the special invalid-date condition. However, it omits other behavioral aspects like what happens with incorrect length or non-digit inputs, or whether it checks real assignment.

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 relatively concise—one dense sentence covering purpose, algorithm, and outcomes. It could be improved by splitting into shorter sentences for readability, but it wastes no words and front-loads the core function.

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 it has only one parameter and an output schema (implied by mention of decoded data), the description covers validation logic, success behavior, and an edge case (invalid date). It is missing details on input length validation and what errors are returned for malformed inputs.

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% and the schema parameter description states 'digits-only identifier'. The tool description enriches this by specifying the context (Polish national ID), required length (11 digits), and the exact validation logic, adding significant meaning 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 explicitly names the resource (PESEL) and action (validates checksum), specifies it's an 11-digit Polish national ID, and details the algorithm. This clearly distinguishes from siblings (nip_validate, regon_validate) by function and context.

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 for PESEL numbers, but provides no explicit guidance on when to use this tool versus the sibling tools for NIP or REGON. No when-not conditions or alternatives are mentioned.

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?

No annotations are provided, so the description must carry the full burden. It fully discloses the checksum algorithm for both 9- and 14-digit numbers, including weight sequences, modulo arithmetic, and how remainder 10 is handled. This is detailed, transparent, and gives the agent full understanding of the validation logic.

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—and front-loads the core purpose before detailing the algorithm. It could be slightly more efficient by omitting the algorithm details or moving them elsewhere, but for a validation tool, including the algorithm is justified 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?

Given that there is no output schema referenced (though context says 'Has output schema: true', no details are provided), the description adequately explains input validation logic. However, it does not mention what the output looks like (e.g., returns a boolean or error message), which would be helpful for completeness.

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% and there is only one parameter, already described as 'digits-only identifier to validate (no spaces or dashes)' in the schema. The description adds no extra semantic meaning beyond what the schema provides, so the 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 that it validates the checksum of a Polish business registry number (REGON). It specifies the exact digit lengths (9 or 14), unlike siblings nip_validate or pesel_validate, making it well differentiated.

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 but offers no guidance on when to use it versus nip_validate or pesel_validate. For example, it could mention that this is for business entities, while PESEL is for individuals and NIP is for tax identification, but it does not.

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