validate_fodselsnummer

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

With no annotations provided, the description fully carries the burden of behavioral disclosure. It clearly states what the tool checks (structure, control digits) and what it does NOT confirm (registration), leaving no ambiguity about its 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 extremely concise (two sentences), front-loaded with a clear directive ('USE THIS'), and contains zero unnecessary words. Every sentence adds essential information.

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?

The description is mostly complete: it explains what the tool validates, what it does not, and when to use it. However, with no output schema, it does not describe the return value (e.g., boolean), which is a minor gap for a validation 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 schema already describes the parameter as an 11-digit number with spaces ignored. The tool description adds that it checks mod-11 control digits, but this is about behavior, not parameter semantics. Therefore, the description adds minimal value beyond the schema, meriting a baseline 3.

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 a Norwegian fødselsnummer, checks the 11-digit form and both mod-11 control digits, and explicitly distinguishes from other validation tools by specifying the country and algorithm.

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', providing clear context for when to use the tool. However, it does not mention alternatives or when not to use it, though the sibling tools are all for different identifiers, so the name already distinguishes.

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