Web Performance Audit

Your knowledge of web performance metrics, thresholds, and tooling APIs may be outdated. Prefer retrieval over pre-training when citing specific numbers or recommendations.

Retrieval Sources

Source	How to retrieve	Use for
web.dev	https://web.dev/articles/vitals	Core Web Vitals thresholds, definitions
Chrome DevTools docs	https://developer.chrome.com/docs/devtools/performance	Tooling APIs, trace analysis
Lighthouse scoring	https://developer.chrome.com/docs/lighthouse/performance/performance-scoring	Score weights, metric thresholds

FIRST: Verify MCP Tools Available

Discover available browser and performance tools before starting. Use the capabilities available for the requested audit. If trace tools are unavailable, continue any useful source or network analysis and state which measurements could not be collected.

If the user wants Chrome DevTools MCP setup, consult its installation guide and use the latest package version. Only change MCP configuration when setup is within the user's authorized scope; otherwise ask first. For clients using command and args, an example server entry is:

"chrome-devtools": {
  "command": "npx",
  "args": ["-y", "chrome-devtools-mcp@latest"]
}

Key Guidelines