Focus a window

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

No annotations are provided, so the description carries the full burden. It discloses that selection affects subsequent commands, which adds a small behavioral context beyond the title, but it does not mention side effects, state persistence, error behavior, or any other relevant traits. Minimal disclosure.

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 sentence that is direct and efficient, with no filler or repetition. It conveys the essential purpose and consequence without wasted words.

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 tool is simple with one required parameter, and the description is adequate for a basic selection action. However, it lacks explicit usage guidance and behavioral depth, leaving questions about context scope and side effects unanswered.

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 input schema already fully documents both parameters with descriptions (100% coverage), so the baseline is 3. The description adds no additional information about target formatting or host behavior beyond what the schema provides.

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 tool selects a window and that subsequent commands will target it, using a specific verb and resource. It does not explicitly contrast with tmux_select_pane, but the window vs pane distinction is evident from the name and title, so it falls short of fully differentiating from siblings.

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 implies usage before subsequent commands that should target the window ('so subsequent commands target it'), giving a clear context. However, it provides no explicit guidance about when to use this tool instead of alternatives like tmux_select_pane, nor does it mention any exclusions or prerequisites.

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