validate_card_number

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

With no annotations, the description carries the full behavioral burden. It discloses the Luhn checksum method and the 16-digit Iranian format, which are useful behavioral details, but says nothing about return values, error behavior, or input normalization. That leaves meaningful gaps for an agent invoking it.

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?

A single front-loaded sentence with no filler. Every element (verb, format, algorithm) helps the agent and there is no redundancy.

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?

For a simple validation tool with no annotations and no output schema, the description covers purpose, format, and algorithm. It omits what the tool returns (boolean, error message, etc.) and any prerequisite normalization, which would matter to an agent. Given the lack of structured output documentation, it is adequate but not complete.

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 0% and the only parameter is a bare string named 'value'. The description compensates by specifying the expected semantic: a 16-digit Iranian bank card number. However, it does not state accepted formats (e.g., spaces, Persian digits) or whether the Luhn check applies only to digits, so some ambiguity remains.

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?

States a specific verb (Validate) and resource (16-digit Iranian bank card number), and adds the Luhn algorithm. This clearly separates it from siblings like validate_sheba or validate_national_id, which validate different identifiers. An agent can tell what the tool does without opening the schema.

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?

No explicit when-to-use guidance or alternatives are provided. It does not clarify when to choose this tool versus bank_from_card or other validation tools. The use case is only implied by the name, so routing help is absent.

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