pin_block_retention_advisory

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

No annotations are provided, so the description carries the disclosure burden. It clearly states the tool 'Returns the PCI PIN Req 4 rule', including the key prohibition that even encrypted PIN blocks may not be retained after the authorization response. It also discloses the credential-free behavior, which is useful operational context for a zero-parameter advisory 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?

Three short, purposeful sentences. The usage trigger is front-loaded, the credential requirement is stated compactly, and the precise advisory content is delivered in the final sentence. No wasted words or repetition of schema fields.

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 zero-parameter advisory tool with no output schema, the description fully covers what the tool does, when to call it, and what it returns. An agent can correctly select and invoke this tool without needing additional structural or behavioral explanation.

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?

The tool has zero parameters and 100% schema description coverage, so the schema needs no explanation. The description adds context about when and why to call the tool, though it does not need to describe any parameters since none exist.

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 ('Call this before designing...') and a precise resource: transaction logging, audit trails, and database schemas handling ISO 8583 field 52 PIN blocks. It also names the returned content (PCI PIN Req 4 rule), making the tool's advisory purpose unambiguous and distinct from the surrounding KMS/data-operation siblings.

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?

Provides an explicit when-to-use condition: before designing any logging, audit trail, or database schema that processes ISO 8583 field 52. It also notes that no AWS credentials are required, which helps an agent avoid unnecessary auth setup. It does not explicitly name alternatives or state when not to use it, but the usage context is clear.

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