jezweb/claude-skills is a collection of skills, commands, plugins, settings, instructions, and hooks that guide the Claude Code CLI through development tasks and produce outputs such as project scaffolds, assets, documents, or deployed services. It is for developers using Claude Code with technologies and services including Cloudflare, React, Tailwind, Shopify, and WordPress. The catalogue entries are the project's own Claude Code workflow components.
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 jezweb/claude-skills --skill responsiveness-checkgit clone --depth 1 https://github.com/jezweb/claude-skillsWrote 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/jezweb/claude-skills/responsiveness-check)<a href="https://agentmods.dev/skills/jezweb/claude-skills/responsiveness-check"><img src="https://agentmods.dev/badge/skills/jezweb/claude-skills/responsiveness-check/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/jezweb/claude-skills/responsiveness-check"><img src="https://agentmods.dev/badge/skills/jezweb/claude-skills/responsiveness-check.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Socket pass
- Snyk warn
- NVIDIA SkillSpector pass
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 | $0.00085 | $0.01666 |
| Opus 5.5 | $0.00034 | $0.00666 |
| Sonnet 5.5 | $0.00017 | $0.00333 |
| Haiku 4.5 | $0.00009 | $0.00167 |
Grade A, and why
responsiveness-check 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 1mo 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 — 153 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Responsiveness Check
Test how a website's layout responds to viewport width changes. Resizes through breakpoints in a single browser session, screenshots each width, compares adjacent sizes, and reports where layouts break.
What this tests: Layout responsiveness — overflow, stacking, navigation transitions, content reflow.
What this does NOT test: General accessibility (ARIA, semantic HTML, heading hierarchy, colour contrast). Those don't vary by viewport width — use the ux-audit skill instead.
Browser Tool Priority
Before starting, detect available browser tools:
- playwright-cli (preferred) — supports resize, named sessions, and sub-agent parallelism. If installed, run
/playwright-clifirst to load the full command reference. - Playwright MCP (
mcp__plugin_playwright_playwright__*) —browser_resizefor viewport changes. - Chrome MCP (
mcp__claude-in-chrome__*) —resize_windowfor viewport changes. Uses the user's logged-in Chrome session.
If none are available, inform the user and suggest installing playwright-cli or Playwright MCP.
Operating Modes
Mode 1: Standard Check
When: "check responsive", "responsiveness check", "test breakpoints"
Test 8 key breakpoints that cover the device spectrum:
| Width | Device Context |
|---|---|
| 320px | Small phone (iPhone SE) |
| 375px | Standard phone (iPhone 14) |
| 768px | Tablet portrait (iPad) |
| 1024px | Tablet landscape / small laptop |
| 1280px | Laptop |
| 1440px | Desktop |
| 1920px | Full HD |
| 2560px | Ultra-wide / 4K |
Process:
- Open the URL in a single browser session (height: 900px)
- Start at 320px. For each breakpoint width: a. Resize the viewport b. Wait briefly for CSS reflow (layout transition) c. Screenshot the above-fold area d. If the page has significant below-fold content, scroll and screenshot e. Run the 8 layout checks (see matrix below) f. Note any issues with severity
- Compare adjacent widths — identify where layout transitions occur
- Write the report
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.
- 1mo ago First seen · 153 lines · 85 tokens per session scan A b7b9f92f088a
responsiveness-check is a skill published in the GitHub repository jezweb/claude-skills (1,075 stars, last pushed 16d ago), licensed MIT. It adds 85 tokens to every session and 1,666 once invoked, about $0.0003 per session on Opus 5.5. 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 2026-08-30.
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