Borrowing it
Nothing to install: this file belongs to warpdotdev/oz-skills. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/warpdotdev/oz-skills/main/.agents/skills/web-performance-audit/SKILL.mdgit clone --depth 1 https://github.com/warpdotdev/oz-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/warpdotdev/oz-skills/web-performance-audit)<a href="https://agentmods.dev/skills/warpdotdev/oz-skills/web-performance-audit"><img src="https://agentmods.dev/badge/skills/warpdotdev/oz-skills/web-performance-audit/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/warpdotdev/oz-skills/web-performance-audit"><img src="https://agentmods.dev/badge/skills/warpdotdev/oz-skills/web-performance-audit.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 | $0.00037 | $0.01898 |
| Opus 5.5 | $0.00015 | $0.00759 |
| Sonnet 5.5 | $0.00007 | $0.00380 |
| Haiku 4.5 | $0.00004 | $0.00190 |
Grade A, and why
web-performance-audit 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.
This is a copy
84% identical to web-perf — 23 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 195 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Web Performance Audit
Audit web page performance using Chrome DevTools MCP tools. This skill focuses on Core Web Vitals, network optimization, and high-level accessibility gaps.
FIRST: Verify MCP Tools Available
Run this before starting. Try calling navigate_page or performance_start_trace. If unavailable, STOP—the chrome-devtools MCP server isn't configured.
Ask the user to add this to their MCP config:
"chrome-devtools": {
"type": "local",
"command": ["npx", "-y", "chrome-devtools-mcp@latest"]
}
Key Guidelines
- Be assertive: Verify claims by checking network requests, DOM, or codebase—then state findings definitively.
- Verify before recommending: Confirm something is unused before suggesting removal.
- Quantify impact: Use estimated savings from insights. Don't prioritize changes with 0ms impact.
- Skip non-issues: If render-blocking resources have 0ms estimated impact, note but don't recommend action.
- Be specific: Say "compress hero.png (450KB) to WebP" not "optimize images".
- Prioritize ruthlessly: A site with 200ms LCP and 0 CLS is already excellent—say so.
Quick Reference
| Task | Tool Call |
|---|---|
| Load page | navigate_page(url: "...") |
| Start trace | performance_start_trace(autoStop: true, reload: true) |
| Analyze insight | performance_analyze_insight(insightSetId: "...", insightName: "...") |
| List requests | list_network_requests(resourceTypes: ["Script", "Stylesheet", ...]) |
| Request details | get_network_request(reqid: <id>) |
| A11y snapshot | take_snapshot(verbose: true) |
Workflow
Copy this checklist to track progress:
Audit Progress:
- [ ] Phase 1: Performance trace (navigate + record)
- [ ] Phase 2: Core Web Vitals analysis (includes CLS culprits)
- [ ] Phase 3: Network analysis
- [ ] Phase 4: Accessibility snapshot
- [ ] Phase 5: Codebase analysis (skip if third-party site)
Phase 1: Performance Trace
- Navigate to the target URL:
navigate_page(url: "<target-url>")
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 · 195 lines · 37 tokens per session scan A 2c82ff8d7c14
web-performance-audit is a skill published in the GitHub repository warpdotdev/oz-skills (822 stars, last pushed 2mo ago), licensed MIT. It adds 37 tokens to every session and 1,898 once invoked, about $0.0001 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 84% identical to web-perf, differing in 23 lines, and is treated as a copy.
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