start

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

With no annotations, the description carries the burden. It discloses key behaviors: async execution, PID return, and pointer to lifecycle tools. But it omits details like error handling, process cleanup, and the exact format of the PID return value. This is adequate but not rich.

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 sentences, front-loaded with the primary action. Every sentence adds value: the action, the async nature, and the follow-up tools. No fluff or repetition.

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 moderate complexity (4 params, 1 required) and presence of an output schema, the description covers the main use case and points to related tools. It could include parameter details, but the lifecycle guidance and async disclosure make it fairly complete for a start tool.

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?

Schema description coverage is 0% and the description does not explain the parameters. Only 'command' is implicitly understood, while cwd, env, and shell are left entirely undocumented. The description fails to compensate for the lack of schema-level descriptions.

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 a specific verb and resource: 'Start a background process and return its PID.' It distinguishes from siblings by emphasizing 'background' and 'asynchronously', which contrasts with the 'run' tool and the post-start lifecycle tools (status, signal, input).

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?

It provides clear context: start a background process, then use status(), signal(), and input() for subsequent interaction. It implies this tool is for launching processes, not managing them. However, it doesn't explicitly mention when to use alternatives like run or list_processes, leaving some room for uncertainty.

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