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capture_window

Take a screenshot of a specific window without bringing it to the foreground or interrupting your workflow, even while watching video or using other applications.

Instructions

Capture a screenshot of a specific window without bringing it to the foreground or stealing focus from the user. Works while the user watches video or works.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
window_idYesWindow ID (HWND, XID hex 0x..., or title substring).
output_pathNoOptional absolute path where the screenshot PNG will be saved. Defaults to an artifact path.

Schema Changelog

Changes observed during successful MCP inspections.

  1. First observedv1.0.0

TDQS

A4/5.0
Behavior3/5

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

No annotations are provided, so the description carries the burden of behavioral disclosure. It does disclose the most important behavior: capturing without foregrounding or stealing focus. However, it does not mention output behavior, failure modes, or what happens with minimized or obscured windows, leaving some ambiguity about the capture result.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is two concise sentences with no filler. The primary action is front-loaded, and the key non-intrusive behavior is stated immediately, making it easy to scan and understand.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

This is a relatively simple tool with two parameters, both fully described in the schema. The description provides the essential operational context about focus preservation. There is no output schema, so return-value details are not specified, but an agent has enough information to invoke it correctly for the intended non-disruptive screenshot use case.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so both window_id and output_path are already well documented in the schema. The description adds no significant parameter-level meaning beyond the schema, which establishes the baseline of 3.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states a specific action ('Capture a screenshot') and a specific resource ('a specific window'), and adds a distinguishing behavioral detail: it does not bring the window to the foreground or steal focus. This differentiates it from all listed siblings, which concern typing, clicking, launching, listing, or window type actions.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description gives clear context for when to use the tool: when a screenshot is needed without disrupting the user, such as 'while the user watches video or works.' It does not explicitly name alternatives or exclusion conditions, but the use case is clear enough for an agent to select it appropriately.

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