tmux_last_pane

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

The description discloses the return value format and the effect of the `window` parameter. Since no annotations are provided, it carries the full burden and does so adequately for a simple toggle action.

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 concise (3 sentences) and front-loaded with the main action. However, the omission of `target` parameter information makes it efficient but incomplete.

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 simple tool with no output schema and low schema coverage, the description is adequate for the primary function but lacks explanation for all parameters. It documents the return value, which is helpful.

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%. The description adds meaning to the `window` parameter but completely ignores the `target` parameter, leaving half the parameters unexplained.

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 action ('Switch to the previously active pane') and resource ('pane'). It distinguishes itself from sibling tools like tmux_select_pane and tmux_last_window by naming 'last-pane'.

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 explains when to use the `window` parameter ('acts on that window; otherwise the current one'), providing clear context. It does not explicitly exclude alternatives, but the purpose is self-evident.

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