Executes these capabilities
Inside this skill
The internal capability tree shows how this skill gets its work done.
- viewport screenshot capture
- layout diffing
- issue description
The contract
Input
- The running site or built pages
- Viewport list (for example 390, 768, 1024, 1440)
Output
- Screenshot set per viewport
- Issue list with element references
Deliverables
- Screenshots and review notes
Use cases
- Pre-ship design QA
- Responsive checks
- Regression detection across deploys
Dependencies and replacements
Dependencies
- A headless browser
Required tools
- Playwright or equivalent
Required permissions
- Run a local server or open the deployed URL
Compatible with
- validation-checklist
- link-checker
Alternatives
- Design review by a human
- Cloud screenshot services
Replaceable components
- The browser tooling
Reliability
Human checkpoints
- Human confirms which issues to fix
Limitations
- Cannot judge taste or content quality
- Screenshots miss interaction states
Failure modes
- Reviewing only desktop widths
- Comparing screenshots without a checklist
- Ignoring reduced-motion and dark mode
Recovery steps
- Add missing viewports and re-shoot
- Review against an explicit layout checklist
- Capture both themes when the site supports them
Validation methods
- A second reviewer finds the same issues from the screenshots
Sources
Entry checked on Jul 31, 2026. Verification status reflects what AgentSkillTree has independently run, not the skill's own claims.
When to use
Use before any deploy where layout matters. Screenshots are evidence: they make visual issues concrete and reviewable without the reviewer running the code.
Verification note
Used on the AgentSkillTree.com MVP in 2026-07: captured 390, 768, 1024, and 1440px screenshots of the home, scenario, skill, and build pages and caught mobile overflow issues before deploy.