verify_pin_data

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

No annotations are provided, so the description carries the full burden. It adds useful behavioral detail: supported key types (V1/V2, P0/B0), DUKPT KSN requirements, and the ISO_FORMAT_1 PAN exception. However, it does not state whether the operation is non-mutating or describe auth/error/rate-limit behavior, leaving some ambiguity.

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 well structured with a front-loaded usage statement, supported key types, and a clean Args list. Although detailed, the detail is necessary given 9 parameters and no schema descriptions; there is little 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?

Given the high complexity (9 params, nested objects, conditional logic) and absence of annotations/output schema, the description covers the invocation contract thoroughly. It still omits response/return details and potential error conditions, but these are not critical for selecting and invoking the 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 description coverage is 0%, but the description documents every parameter with formats, examples, and conditional requirements (e.g., dukpt_attributes required with BDK, encryption_wrapped_key changes key meaning, PAN optional only for ISO_FORMAT_1). This fully compensates for the schema gap.

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 opens with a concrete use case ('implementing PIN verification at an issuer host') and clearly states the operation: validating a cardholder-entered PIN against a stored IBM 3624 offset or Visa PVV. This differentiates it from sibling generation/verification tools by naming the specific PIN verification schemes and formats.

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?

It explicitly says when to call it: during issuer-host PIN verification and for end-to-end validation before production. It does not explicitly call out alternatives or when not to use it, but the context is clear enough for an agent to route to this tool.

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