Available MCP Tools

The screenshot MCP server provides 5 tools:

Tool	Purpose	Key Parameters
`list_windows`	Discover all visible windows	None
`list_displays`	List all monitors/displays	None
`screenshot_window`	Capture specific window	`window_id` or `window_title`, `save_dir`
`screenshot_screen`	Capture entire display	`display_id`, `save_dir`
`screenshot_region`	Capture screen region	`x`, `y`, `width`, `height`, `save_dir`

Testing Workflow

Before capturing, identify the correct window:

1. Call list_windows to get all visible windows
2. Find target by app name or title
3. Note the window ID for screenshot_window

Window matching strategies:

Choose the appropriate capture method:

After capturing, analyze the screenshot for:

For detecting UI changes between versions:

Create baseline: Capture screenshots with save_dir parameter
Store organized: Screenshots save as {save_dir}/YYYY-MM-DD/YYYYMMDD_HHMMSS.png
Compare later: Capture new screenshots and compare visually

When comparing screenshots:

Capture current state screenshot
Load baseline screenshot from saved location
Compare visually for differences:
- Layout shifts
- Missing/extra elements
- Color or style changes
- Text content differences

Report findings with specific observations about what changed.

For applications spanning multiple monitors:

Platform	Status	Notes
macOS	Supported	Requires Screen Recording permission
Windows	Planned	Future release
Linux	Planned	Future release

On macOS, grant Screen Recording permission in System Settings > Privacy & Security > Screen Recording.

For practical testing examples, see:

examples/electron-app-testing.md - Testing an Electron application login flow

For detailed patterns:

references/testing-patterns.md - Common UI testing patterns and strategies