generate_pin_data

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

With no annotations, the description carries the behavioral burden and largely succeeds: it discloses supported schemes with JSON shapes, required key types (V1/V2 PVK, P0 PEK or wrapped KEK), and the ISO_FORMAT_1 PAN exception. It omits the exact response structure and error/side-effect conditions, but the core operational behavior is clearly conveyed.

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 long, but its length is justified by the tool's complexity. It front-loads trigger conditions, then uses compact structured examples and an Args list so each sentence earns its place.

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 7 parameters, nested generation_attributes, and four PIN block formats, the description covers scheme variants, key mapping, and PAN/format special cases. The main gap is the absent output schema and no explicit response-field or error documentation, which prevents a full 5.

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%, so the description must compensate, and it fully does. Every parameter receives operational meaning: ARN/alias key identifiers, scheme-specific generation_attributes examples, accepted PIN block formats, PAN length and requirement rules, PIN length range, and wrapped-key behavior. This far exceeds the bare input 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?

States a specific verb/resource: IBM 3624 and Visa PVV PIN generation, PIN offsets for card personalization, and test PIN block production. The algorithm-specific contexts and 'issuer function' qualifier distinguish this from sibling translation/verification tools even without naming them.

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?

Explicitly opens with 'Call this when' and gives three concrete use cases, plus warns that it is an issuer-side function to use with care in acquirer contexts. It does not explicitly say when to use translate_pin_data or verify_pin_data instead, so the when-not guidance is somewhat implicit.

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