yubikey-list

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

With no annotations, the description bears full responsibility for behavioral disclosure. It only states the action and result, omitting details like required permissions, error behavior (e.g., no YubiKeys connected), or performance characteristics. This leaves the agent with minimal understanding of side effects or constraints.

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, concise sentence that efficiently conveys the core functionality. It could add a brief note on edge cases (e.g., empty result) without losing conciseness, but it is appropriately sized for a simple tool.

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 tool's simplicity (no parameters, no output schema, no annotations), the description covers the basic purpose. It lacks details on return format or behavior when no YubiKeys are present, but for a list operation, the output is implicitly a list of serial numbers, which is sufficient.

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, and schema documentation coverage is 100% (trivially). The description adds nothing about parameters because none exist, but baseline for 0 parameters is 4. No parameter information is missing.

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 lists all connected YubiKeys with serial numbers. The verb 'list' and resource 'connected YubiKeys' are specific, and it contrasts with sibling tools that focus on specific features like FIDO or PIV, making its purpose distinct.

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 usage for discovering available YubiKeys before using feature-specific tools, but it lacks explicit guidance on when to use this over alternatives or any prerequisites. No exclusions or alternatives are mentioned.

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