ssh_agent_ensure

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

Without annotations, the description carries full burden. It discloses that it starts a new agent and sets environment variables, but does not detail exactly which variables are set or potential side effects like overwriting existing agent sockets. Still transparent enough for common use.

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?

Two concise sentences: first describes what it does, second tells when to use it. No wasted words, effective front-loading of purpose.

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?

The description covers essential aspects for a simple tool: purpose and usage context. It lacks details about what 'reachable' means or specific error indicators, but is adequate given no parameters or output schema.

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 the description does not need to provide parameter information. Baseline score of 4 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?

The description clearly states the verb 'ensure' and the resource 'ssh-agent', specifying that it starts a new agent if needed and sets environment variables. This distinguishes it from sibling tools like ssh_exec, ssh_download, etc., which perform actual SSH operations.

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 tells the agent to use this tool 'FIRST when SSH operations fail with agent-related errors', providing clear guidance on when to invoke it.

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