Create a new session

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

With no annotations, the description must carry the full burden of behavioral disclosure. It does disclose a key behavior—creating a detached session—which implies the session runs in the background after the tool returns. However, it does not mention what happens if the session already exists, how the host default is used, or any side effects beyond session creation.

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 a single sentence that is direct and free of filler. Every word contributes meaning ('detached', 'collaborate'), and it is appropriately sized for the tool's simplicity.

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 has no output schema and only 3 parameters, the description is minimally adequate. It covers the core action and a key behavioral trait (detached), but lacks guidance on return values, error cases, and interaction with the host parameter. It is sufficient for the simplest use cases but leaves gaps for an agent needing deeper context.

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 coverage is 100%, and the description adds no parameter-specific details beyond what the schema already documents. It does not explain how 'command' or 'host' are used in practice, so no extra semantics are provided.

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 it creates a detached tmux session, using the specific verb 'create' and identifying the resource (session). The 'detached' qualifier distinguishes it from opening or attaching to an existing session, though it does not explicitly name sibling alternatives.

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 provides no explicit guidance on when to use this tool versus alternatives like tmux_open_session or tmux_new_window. The 'collaborate in' phrase implies a collaborative use case, but there is no direct when-to-use or when-not-to-use guidance.

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