optimise-seo

これはレビュー時に保存された抜粋です。完全で最新の内容は外部ソースを確認してください。

---
name: optimise-seo
description: Optimises SEO and technical foundations for Next.js App Router apps, covering sitemaps, robots, meta tags, structured data, canonical URLs, redirects, indexing policy, hreflang and internationalisation, Core Web Vitals, programmatic SEO, security headers, privacy/consent, and error-page resilience. Use when asked to "improve SEO", "add a sitemap", "fix meta tags", "add structured data", "set canonical URLs", "set up redirects", "fix soft 404s", "add hreflang", "add security headers", "add cookie consent", "improve Core Web Vitals", "audit SEO", or "build SEO pages at scale". Performs no visual redesigns; for visual direction use ui-design, for page-level UI quality use ui-audit, for writing the article itself use the external ghostwriter skill with platform blog. Does not cover llms.txt or AI-agent readability; research current specs for that work.
---

# Optimise SEO

- **IS:** crawlability, metadata, structured data, canonicals, redirects, hreflang, Core Web Vitals, programmatic SEO, security/privacy headers, and error-page status behaviour for Next.js App Router apps.
- **IS NOT:** visual redesigns or layout changes (use `ui-design`), or page-level UI quality review (use `ui-audit`). Making a site readable by AI agents (llms.txt, MCP discovery, WebMCP) is out of scope; research current specs rather than relying on static SEO guidance.

Allowed surface: metadata, structured data, semantic HTML, internal links, alt text, `app/sitemap.ts`, `app/robots.ts`, `next.config.ts` redirects and headers, error pages, performance tuning. Never touch component styling or layout.

## Workflow

Copy and track this checklist:

```text
SEO progress:
- [ ] Step 1: Inventory routes and decide index intent per route
- [ ] Step 2: Fix crawl/index foundations (sitemap, robots, canonicals, redirects, status codes)
- [ ] Step 3: Implement metadata + structured data
- [ ] Step 4: Improve semantics, internal links, and Core Web Vitals
- [ ] Step 5: Validate with references/seo-checklist.md and report evidence
```

Before writing code for steps 2-4, read [references/nextjs-implementation.md](references/nextjs-implementation.md): App Router patterns (Metadata API, `generateMetadata`, sitemap index, JSON-LD component, OG image generation, `headers()`/`redirects()` config).

## Must-have on every site

- `app/sitemap.ts` lists all public URLs; `app/robots.ts` links to it
- Canonical URL set and consistent on every page (one host, one casing, one trailing-slash policy)
- Unique title and description per page via `metadata` or `generateMetadata`
- OpenGraph + Twitter Card tags with a 1200x630 image
- JSON-LD: Organization and WebSite on the homepage, BreadcrumbList on inner pages, plus Article/Product/FAQ where the content type matches. Define each entity once in a `@graph` with a stable `@id` and reference it by `@id` instead of duplicating it inline (`@id` conventions and the per-type code: `references/nextjs-implementation.md`)
- One h1 per page with logical h2-h6 hierarchy
- Descriptive alt text, internal links between related pages, CWV in target (LCP < 2.5s, INP < 200ms, CLS < 0.1)

## Programmatic SEO (pages at scale)

- Validate search demand for the pattern before generating pages
- Each page needs unique value backed by defensible data; templated text swaps are doorway pages
- Clean subfolder URLs, hub-and-spoke linking, breadcrumbs on every page
- Index only strong pages; `noindex` the long tail and monitor indexation and cannibalisation in Search Console
- Applies to single pages too: `noindex` a thin page and omit it from the sitemap until it carries unique content, then add an internal link and index it

## SEO audit (triage order)

1. Crawl/index: robots, sitemap, stray `noindex`, canonicals, redirect chains, soft 404s
2. Technical: HTTPS, Core Web Vitals, mobile/desktop parity
3. On-page: titles/H1 uniqueness, internal links, remove or `noindex` thin pages
4. Orphans: indexable pages (metadata, canonical,