ssh_key_list

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

With no annotations, the description carries the full burden of behavioral disclosure. It clearly specifies the success/failure boundary: isError only when ~/.ssh exists but cannot be read, while absent or empty ~/.ssh is successful and returns an ssh-keygen hint. This is unusually precise.

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 three tight sentences, each carrying useful information: what is listed, when to use it, and exact error semantics. It is front-loaded with the core behavior and has no filler.

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?

Despite having no output schema, the description states the returned key fields and the failure condition. For a zero-parameter listing tool, this is complete enough for an agent to call and interpret the result correctly.

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, so the baseline is 4. The description adds relevant context by naming the target directory (~/.ssh/), which is all the parameter semantics needed here.

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 uses a specific verb 'List' with a clear resource ('all SSH private keys in ~/.ssh/') and states the output fields (type, fingerprint, loaded state). This distinguishes it from sibling tools like ssh_key_load or ssh_agent_ensure without requiring schema inspection.

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 explicitly says 'Use this to find which keys are available and which ones need to be loaded,' giving a concrete use case. It does not explicitly name alternatives or when-not-to-use conditions, but the use case is clear enough to route an agent.

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