Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add chunlea/screenshot-mcp --skill screenshot-testinggit clone --depth 1 https://github.com/chunlea/screenshot-mcpWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/chunlea/screenshot-mcp/screenshot-testing)<a href="https://agentmods.dev/skills/chunlea/screenshot-mcp/screenshot-testing"><img src="https://agentmods.dev/badge/skills/chunlea/screenshot-mcp/screenshot-testing/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/chunlea/screenshot-mcp/screenshot-testing"><img src="https://agentmods.dev/badge/skills/chunlea/screenshot-mcp/screenshot-testing.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00081 | $0.01051 |
| Opus 5 | $0.00041 | $0.00526 |
| Sonnet 5 | $0.00016 | $0.00210 |
| Haiku 4.5 | $0.00008 | $0.00105 |
Grade A, and why
Screenshot Testing scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 9d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 150 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Screenshot Testing
A guide for conducting effective UI testing using screenshots. This skill covers the screenshot-mcp tools, testing workflows, and comparison strategies for native application testing.
Configuration
Check for plugin settings at .claude/screenshot.local.md before taking screenshots.
Settings file format:
---
default_save_dir: /path/to/screenshots
---
When settings file exists:
- Read the file using the Read tool
- Parse YAML frontmatter to extract
default_save_dir - Use this path as
save_dirwhen user wants to save screenshots - If user specifies a different path, use their path instead
When settings file does not exist:
- Ask user if they want screenshots saved
- If yes, ask for save location or suggest creating settings file
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
Step 1: Identify Target Window
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:
- By app name: Look for
appfield (e.g., "Electron", "Simulator") - By title: Use
window_titleparameter for fuzzy matching - By bounds: Check
boundsto identify window by size/position
Step 2: Capture Screenshot
Choose the appropriate capture method:
- Single window: Use
screenshot_windowwith window ID or title - Full screen: Use
screenshot_screenfor entire display - Specific area: Use
screenshot_regionfor precise coordinates
What ships with it
2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 9d ago First seen · 150 lines · 81 tokens per session scan A 6c4aaf4ae3bf
Screenshot Testing is a skill published in the GitHub repository chunlea/screenshot-mcp (1 stars, last pushed 7mo ago), licensed MIT. It adds 81 tokens to every session and 1,051 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
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