pan_change_advisory

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

With no annotations, the description carries the burden. It states the tool 'works without AWS credentials' and 'returns' a rule, implying a read-only advisory with no side effects. This is sufficient transparency for a zero-parameter advisory tool, though it does not explicitly declare non-mutating behavior.

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 compact and front-loaded: the primary use case is stated first, followed by the credential note and the returned rule. Every sentence contributes meaningful information with 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 zero-parameter advisory tool with no output schema, the description fully covers what the tool is for, when to call it, credential requirements, and what rule it returns. No critical information is missing.

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 no parameters, so there is nothing for the description to explain. The schema coverage is 100% and the description adds useful context about when the advisory applies, which 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?

Clearly states what the tool does: returns the PCI PIN rule that the PAN must not change during PIN block translation. It also identifies when it applies (PIN translation flows with differing PAN formats, PCI PIN Req 3-3 / ISO 9564 questions), distinguishing it from transactional siblings like translate_pin_data.

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 explains when to call it: before implementing PIN translation flows where PAN may differ, or when asked about specific PCI/ISO requirements. It does not mention alternatives or exclusions, but the niche advisory purpose makes the use context clear enough.

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