Need For Speed Agent Skill

Performance Audit

Run a performance audit on a WordPress site to measure Core Web Vitals and page composition, then provide actionable recommendations.

How to Run

• Determine which site to audit. If the user hasn't specified, ask them or use the site from the current context.
• Ensure the site is running (use site_start if needed).
• Call need_for_speed with the site name and path (defaults to /).
• Analyze the results using the interpretation guide below.
• Present a clear summary with specific, actionable recommendations.

Interpreting Results

Core Web Vitals Thresholds

| Metric | Good | Needs Improvement | Poor |

|--------|------|-------------------|------|

| TTFB | < 800 ms | 800–1800 ms | > 1800 ms |

| FCP | < 1800 ms | 1800–3000 ms | > 3000 ms |

| LCP | < 2500 ms | 2500–4000 ms | > 4000 ms |

| CLS | < 0.1 | 0.1–0.25 | > 0.25 |

Page Composition Benchmarks

• DOM elements: Concern if > 1500
• Total page weight: Concern if > 3 MB
• Total requests: Concern if > 80
• Scripts: Concern if > 20 scripts or > 500 KB total
• Stylesheets: Concern if > 10 stylesheets or > 200 KB total

Common WordPress Recommendations

Based on the metrics, suggest specific actions:

• High TTFB: Enable page caching (e.g., wp_cli: plugin install wp-super-cache --activate), check for slow database queries, consider object caching.
• High LCP / FCP: Check for render-blocking CSS/JS, add lazy loading for below-the-fold images, defer non-critical scripts.
• Large JS payload: Identify heavy plugins from the scripts URL list, suggest deactivating unused plugins, check for jQuery dependency chains.
• Large CSS payload: Look for unused theme stylesheets, check for multiple Google Fonts loads.
• Many HTTP requests: Suggest reducing plugin count, enabling asset concatenation.
• High CLS: Check for images without explicit width/height dimensions, ads or dynamic content injection, web fonts causing layout shifts.
• Large DOM: Check theme template complexity, excessive nesting in block content, too many wrapper elements.

Important Notes

• These are synthetic measurements on a local dev server. TTFB will be artificially low compared to production. Focus on relative comparisons (before/after changes) rather than absolute values.
• CLS is measured during page load only, not during user interaction.
• INP (Interaction to Next Paint) is not measured — it requires real user interaction patterns.
• Page weight may undercount if some resources report 0 transfer size (e.g., service worker cached resources).