seo-fundamentalslisted

# SEO fundamentals Scope: seo-fundamentals — meta/OG tags, structured data, and sitemap/robots for discoverability and correct crawling/sharing. **Duty split with `core-web-vitals-for-ui`: this skill owns discoverability (can the page be found, indexed, and correctly represented when shared); `core-web-vitals-for-ui` owns the performance half (LCP/INP/CLS) that search engines also factor into ranking — a page can be perfectly discoverable per this skill and still rank poorly on Core Web Vitals, and vice versa, so treat the two as complementary checklists, not overlapping ones.** ## 1. Meta tags and Open Graph - **Every public page needs a unique, accurate `<title>` and `<meta name="description">`** — these are what search results and most share previews fall back to when Open Graph tags (below) are absent. A site-wide default title/description on every page (or worse, none) makes every page look identical to a crawler and a search results page alike. - **Open Graph (`og:*`) tags control how a link renders when shared** on platforms that read them (Slack, Discord, iMessage, most social platforms) — at minimum set `og:title`, `og:description`, `og:image`, `og:url`, and `og:type`. Without them, a shared link falls back to whatever the platform can scrape from `<title>`/`<meta description>`/the first image, which is inconsistent and often wrong. - **`og:image` needs an absolute URL** (not relative) and a reasonable fixed size (1200×630 is the common safe de