yubikey-piv-keys-info

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

No annotations are provided, so the description carries the burden for behavioral transparency. It names the outputs but does not explicitly state that the tool is read-only, what happens if a slot is empty, or if any authentication is required. For a simple query tool, this is adequate but not comprehensive.

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 a single sentence that immediately conveys the tool's purpose and what it returns. Every word is informative, with no fluff or repetition. It is front-loaded and efficient.

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 that the schema fully documents parameters and the description lists the return fields, the tool definition is mostly complete. It lacks mention of hardware prerequisites or error conditions, but for a straightforward query tool, this is a minor gap. An output schema is absent but not critical here.

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 input schema provides complete descriptions for both parameters (serial and slot), so description coverage is 100%. The tool description adds no additional meaning beyond the schema, meeting the baseline of 3.

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 clearly states the tool gets private key metadata for a PIV slot, listing specific attributes (key type, origin, PIN policy, touch policy). This distinguishes it from sibling tools like yubikey-piv-info (likely general PIV info) and others focused on different YubiKey functions.

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?

The description implies the tool is for querying PIV slot key details, and sibling tools cover different areas (FIDO, OpenPGP, OTP), providing implicit context. However, there is no explicit guidance on when to use this versus yubikey-piv-info, nor any mention of prerequisites or when not to use it.

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