validate.iban

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states the tool is deterministic, covers ~85 countries, performs country-specific length and ISO 7064 mod-97 checksum validation, and returns specific fields. It does not mention error handling for invalid input, but the schema addresses input format. Overall, good transparency 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?

The description is two sentences with no filler. The first sentence states the action and method, the second lists outputs and a recommendation. Key information is front-loaded and every sentence serves a purpose.

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 lack of output schema, the description compensates by listing the return fields (valid flag, normalized form, grouped form, country, check digits, BBAN). It also mentions determinism and country coverage. For a single-parameter validation tool, the description is quite complete, though it could briefly mention what happens on invalid input.

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% with one parameter 'iban' already described as 'IBAN to validate (spaces/hyphens allowed, case-insensitive)'. The description adds context about canonicalization and formatting but does not provide essential parameter meaning beyond the schema. 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 validates an IBAN using full ISO 13616 checks, not just regex. It specifies what it returns (valid flag, normalized form, country, etc.), distinguishing it from simpler validation methods. The verb 'validate' with resource 'IBAN' is specific and unambiguous.

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 when to use this tool: when proper IBAN validation and canonicalization are needed, instead of doing checksum math in an LLM. It provides context but does not explicitly state when not to use it or mention sibling tools like validate.bic as alternatives. The guidance is clear but could be more explicit.

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