ssh_key_list

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

Adds genuinely non-obvious behavior beyond the readOnlyHint/openWorldHint annotations: isError is raised only when ~/.ssh exists but is unreadable, while a missing or empty directory is a successful result with a ssh-keygen hint. That error semantics is valuable, though file permissions, symlink handling, and public-key visibility are unstated.

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 tight sentences: what it returns first, then when to use it, then error semantics. Every sentence carries information and nothing is repeated from structured 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?

A zero-parameter read tool with no output schema, and the description covers the returned fields plus the success/failure boundary. Nothing an agent needs in order to call it and interpret the result 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 takes no parameters, so there is nothing for the description to document and the baseline of 4 applies. The description does not need to compensate for any schema gap.

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?

Specific verb (list) plus resource (SSH private keys) plus scope (~/.ssh/), and it names the returned fields: type, fingerprint, agent-loaded status. This is clearly distinguishable from ssh_key_load, which it implicitly signals as the follow-up action.

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?

States an explicit usage context: find which keys are available and which need loading, which routes the agent toward ssh_key_load for the second step. It doesn't state any when-not conditions or name the sibling tool outright, so it stops short of a 5.

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