validate_be_nrn

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

With no annotations provided, the description takes full responsibility. It discloses that it checks the 11-digit form, performs mod-97 validation, handles the born-from-2000 rule, and validates only structure (not actual registration). This is transparent about its capabilities and limitations.

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 consists of two short sentences with no filler. The first sentence is an actionable command for when to use the tool, and the second explains the validation logic. Every word serves a purpose, making it highly efficient.

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's simplicity (single parameter, no output schema, no nested objects), the description is fully complete. It covers purpose, validation rules, limitations (structure only), and the special born-from-2000 rule. No additional context is needed for an agent to correctly use this tool.

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 parameter description in the schema already provides basic meaning. The description adds value by clarifying that punctuation is ignored and by detailing the validation steps (11-digit, mod-97, born-from-2000), which goes beyond the schema's minimal description.

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 purpose: to verify a Belgian National Register Number. It specifies the verb ('verify'), the resource ('Belgian National Register Number'), and distinguishes it from sibling validation tools by naming the specific number type. The phrase 'USE THIS' reinforces its specific purpose.

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 explicitly says 'USE THIS to verify... before relying on it,' which tells when to use. It also clarifies that it 'Validates structure only,' implying it does not check existence, which is a usage guideline. However, it does not explicitly state when not to use it or provide alternatives, missing some depth.

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