spawn

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It does convey a meaningful detail (tmux session), which suggests a detached, long-running process, but it omits important behaviors: whether the call blocks or returns immediately, what happens if the session name is already taken, whether the process runs in the background, and how the agent later knows the session is ready for interaction.

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?

A single, tightly worded sentence that gets straight to the point: verb, resource, and medium. No filler words, no redundant restatement of the tool name, and the key behavior (starting in tmux) is front-loaded.

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?

For a tool that launches an external process, the description is too thin. It does not say what the tool returns, whether it is asynchronous, how to confirm startup, or how the session is subsequently managed. The rich parameter schema covers only input semantics; the absence of an output schema and annotations makes these gaps more significant.

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 100%, so the baseline is 3. Each parameter already has a clear schema description (unique session name, initial prompt, working directory). The tool description adds nothing beyond what the schema provides, but it does not need to since the schema is already explicit.

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 ('Start'), a concrete resource ('a Claude Code instance'), and a distinct delivery mechanism ('in a tmux session'). It clearly distinguishes itself from the sibling tools (read, send, kill, list), which all operate on already-running sessions rather than creating one.

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?

No explicit guidance is given on when to use this tool versus the siblings. The description implies it is the entry point for creating a session, but it never states that send/read/kill/list are for interacting with the spawned session, nor does it mention any prerequisites or conditions that would make an alternative preferable.

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