capture_active_window

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

No annotations are provided, so the description bears the full behavioral burden. It usefully discloses the underlying mechanism ('uses hyprctl activewindow geometry'), which implies a Hyprland dependency, but it does not mention side effects (e.g., whether a capture file is saved), permissions, or error behavior when no window is focused.

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 front-loaded sentence with zero waste. The parenthetical adds concrete implementation context without diluting the primary action.

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 zero-parameter screenshot tool, the description covers the action and its mechanism, and the output schema handles return values. The only meaningful gap is the absence of any safety or side-effect disclosure, but the tool's simplicity keeps this from being a severe omission.

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 tool takes zero parameters and the schema is empty, so the baseline score of 4 applies per the rubric. There are no parameters whose semantics need additional explanation.

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?

States a specific verb ('Screenshot') and a precisely scoped resource ('currently focused window'). The 'currently focused' qualifier implicitly distinguishes it from sibling tools like capture_window (a specific window) and capture_monitor (a full monitor), so an agent can select it without opening other schemas.

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 gives no explicit guidance on when to use this tool versus capture_window, capture_monitor, or capture_region. It also omits any prerequisites or exclusions, leaving the agent to infer selection criteria from the name alone.

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