Give every page its own meta description

website/app/[category]/[slug]/page.tsx

@@ -3,7 +3,7 @@ import Link from "next/link";
 import { notFound } from "next/navigation";
 import ReactMarkdown from "react-markdown";
 import remarkGfm from "remark-gfm";
-import { getPatternBySlug, getPatternSlugs, titleToSlug } from "@/lib/markdown";
+import { extractSummary, getPatternBySlug, getPatternSlugs, titleToSlug } from "@/lib/markdown";
 import { getCategoryConfig, isValidCategory } from "@/app/lib/category-config";
 import { basePath } from "@/lib/config";
 import { PatternCategory, PatternContent } from "@/lib/types";
@@ -57,7 +57,9 @@ export async function generateMetadata({ params }: PatternPageProps): Promise<Me
   }
 
   const resolved = resolvePattern(category as PatternCategory, slug);
-  return resolved ? { title: resolved.pattern.title } : {};
+  return resolved
+    ? { title: resolved.pattern.title, description: extractSummary(resolved.pattern.content) }
+    : {};
 }
 
 interface ResolvedPattern {

website/app/[category]/page.tsx

@@ -28,7 +28,8 @@ export async function generateMetadata({ params }: CategoryPageProps): Promise<M
     return {};
   }
 
-  return { title: getCategoryConfig(category as PatternCategory).labelPlural };
+  const config = getCategoryConfig(category as PatternCategory);
+  return { title: config.labelPlural, description: config.listDescription };
 }
 
 export default async function CategoryPage({ params }: CategoryPageProps) {

website/app/contributors/[authorId]/page.tsx

@@ -21,7 +21,12 @@ export async function generateMetadata({ params }: ContributorDetailPageProps):
   const { authorId } = await params;
   const contributor = getContributorDetailById(authorId);
 
-  return contributor ? { title: contributor.name } : {};
+  return contributor
+    ? {
+        title: contributor.name,
+        description: `Patterns, anti-patterns, and obstacles contributed by ${contributor.name}.`,
+      }
+    : {};
 }
 
 export default async function ContributorDetailPage({ params }: ContributorDetailPageProps) {

website/app/contributors/page.tsx

@@ -6,9 +6,11 @@ import { siteConfig } from "@/config/site";
 import styles from "./page.module.css";
 
 const pageTitle = "Contributors";
+const intro = "Thank you to all the contributors who have documented patterns, anti-patterns, and obstacles.";
 
 export const metadata: Metadata = {
   title: pageTitle,
+  description: intro,
 };
 
 export default function ContributorsPage() {
@@ -18,9 +20,7 @@ export default function ContributorsPage() {
     <div className={styles.container}>
       <header className={styles.header}>
         <h1 className={styles.title}>{pageTitle}</h1>
-        <p className={styles.description}>
-          Thank you to all the contributors who have documented patterns, anti-patterns, and obstacles.
-        </p>
+        <p className={styles.description}>{intro}</p>
         <p className={styles.description}>
           Want to contribute? Read the{" "}
           <Link

website/app/page.tsx

@@ -1,10 +1,19 @@
+import type { Metadata } from "next";
 import Link from "next/link";
 import styles from "./page.module.css";
 import { getPatternSlugs, getAllPatterns } from "@/lib/markdown";
 import { getGraphData } from "@/lib/graph-data";
 import RelationshipGraph from "./components/RelationshipGraph";
 import SearchBar from "./components/SearchBar";
 
+const intro =
+  "A collection of emerging patterns, anti-patterns and obstacles for effective AI-augmented software development. " +
+  "Learn how to collaborate successfully with AI coding assistants and avoid common pitfalls.";
+
+export const metadata: Metadata = {
+  description: intro,
+};
+
 export default function Home() {
   const patternsCount = getPatternSlugs("patterns").length;
   const antiPatternsCount = getPatternSlugs("anti-patterns").length;
@@ -20,10 +29,7 @@ export default function Home() {
     <div className={styles.container}>
       <section className={styles.hero}>
         <h1>Augmented Coding Patterns</h1>
-        <p>
-          A collection of emerging patterns, anti-patterns and obstacles for effective AI-augmented software development.
-          Learn how to collaborate successfully with AI coding assistants and avoid common pitfalls.
-        </p>
+        <p>{intro}</p>
         <div className={styles.searchContainer}>
           <SearchBar patterns={allPatterns} />
         </div>

website/app/pattern-catalog/page.tsx

@@ -1,7 +1,7 @@
 import type { Metadata } from "next";
 import styles from "./page.module.css";
 import { PATTERN_CATALOG_GROUPS } from "./constants";
-import { getAllPatterns } from "@/lib/markdown";
+import { extractSummary, getAllPatterns } from "@/lib/markdown";
 import { getAuthorById } from "@/lib/authors";
 import CatalogView from "./CatalogView";
 import { CatalogGroupData, CatalogPreviewItem } from "./types";
@@ -11,56 +11,9 @@ const catalogTitle = "Complete Catalog";
 
 export const metadata: Metadata = {
   title: catalogTitle,
+  description: "Every pattern, anti-pattern, and obstacle in one filterable catalog, each with a short summary and its authors.",
 };
 
-function extractSummary(markdown: string): string | undefined {
-  const lines = markdown.split("\n");
-  const summaryLines: string[] = [];
-
-  for (const line of lines) {
-    const trimmed = line.trim();
-
-    if (trimmed.length === 0) {
-      if (summaryLines.length > 0) {
-        break;
-      }
-      continue;
-    }
-
-    if (/^#{1,6}\s/.test(trimmed)) {
-      continue;
-    }
-
-    if (/^[-*]\s/.test(trimmed)) {
-      continue;
-    }
-
-    if (/^>/.test(trimmed)) {
-      continue;
-    }
-
-    const plain = trimmed
-      .replace(/\*\*(.*?)\*\*/g, "$1")
-      .replace(/_(.*?)_/g, "$1")
-      .replace(/`(.*?)`/g, "$1")
-      .replace(/\[(.*?)]\((.*?)\)/g, "$1");
-
-    summaryLines.push(plain);
-
-    if (summaryLines.join(" ").length >= 220) {
-      break;
-    }
-  }
-
-  const summary = summaryLines.join(" ").trim();
-
-  if (!summary) {
-    return undefined;
-  }
-
-  return summary.length > 240 ? `${summary.slice(0, 237).trimEnd()}…` : summary;
-}
-
 function resolveAuthorNames(authorIds: string[] | undefined): string[] {
   if (!authorIds || authorIds.length === 0) {
     return [];

website/app/talk/page.tsx

@@ -16,6 +16,7 @@ const currentMapTitle = "Patterns for Coding with AI";
 
 export const metadata: Metadata = {
   title: currentMapTitle,
+  description: "Interactive maps of the patterns, anti-patterns, and obstacles from the Augmented Coding talks, with links to the recorded walkthroughs.",
 };
 
 type MapIndex = Record<string, { name: string; category: string; slug: string }>;

website/lib/markdown.ts

@@ -61,6 +61,58 @@ function validateSlug(slug: string): void {
   }
 }
 
+export function extractSummary(markdown: string): string | undefined {
+  const lines = markdown.split('\n')
+  const summaryLines: string[] = []
+
+  for (const line of lines) {
+    const trimmed = line.trim()
+
+    if (trimmed.length === 0) {
+      if (summaryLines.length > 0) {
+        break
+      }
+      continue
+    }
+
+    if (/^#{1,6}\s/.test(trimmed)) {
+      continue
+    }
+
+    if (/^[-*]\s/.test(trimmed)) {
+      continue
+    }
+
+    if (/^>/.test(trimmed)) {
+      continue
+    }
+
+    if (/^(closely\s+)?related:/i.test(trimmed)) {
+      continue
+    }
+
+    const plain = trimmed
+      .replace(/\*\*(.*?)\*\*/g, '$1')
+      .replace(/_(.*?)_/g, '$1')
+      .replace(/`(.*?)`/g, '$1')
+      .replace(/\[(.*?)]\((.*?)\)/g, '$1')
+
+    summaryLines.push(plain)
+
+    if (summaryLines.join(' ').length >= 220) {
+      break
+    }
+  }
+
+  const summary = summaryLines.join(' ').trim()
+
+  if (!summary) {
+    return undefined
+  }
+
+  return summary.length > 240 ? `${summary.slice(0, 237).trimEnd()}…` : summary
+}
+
 export function slugToTitleCase(slug: string): string {
   return slug
     .split('-')

website/tests/unit/components/pages.test.tsx

@@ -1,9 +1,9 @@
 import { render, screen } from '@testing-library/react'
 import { metadata as siteMetadata } from '@/app/layout'
-import Home from '@/app/page'
+import Home, { metadata as homeMetadata } from '@/app/page'
 import CategoryPage, { generateMetadata as generateCategoryMetadata } from '@/app/[category]/page'
 import PatternPage, { generateMetadata as generatePatternMetadata } from '@/app/[category]/[slug]/page'
-import { metadata as contributorsMetadata } from '@/app/contributors/page'
+import ContributorsPage, { metadata as contributorsMetadata } from '@/app/contributors/page'
 import { generateMetadata as generateContributorMetadata } from '@/app/contributors/[authorId]/page'
 import { metadata as patternCatalogMetadata } from '@/app/pattern-catalog/page'
 import { metadata as talkMetadata } from '@/app/talk/page'
@@ -24,6 +24,7 @@ jest.mock('@/lib/markdown', () => ({
   getAllPatterns: jest.fn(() => []),
   getPatternBySlug: jest.fn(),
   titleToSlug: jest.requireActual('@/lib/markdown').titleToSlug,
+  extractSummary: jest.requireActual('@/lib/markdown').extractSummary,
 }))
 
 jest.mock('@/lib/contributors', () => ({
@@ -122,6 +123,63 @@ describe('Page titles', () => {
   })
 })
 
+describe('Page descriptions', () => {
+  afterEach(() => {
+    mockGetPatternSlugs.mockReset()
+    mockGetPatternBySlug.mockReset()
+    mockGetContributorDetailById.mockReset()
+  })
+
+  it('describes the home page with its intro text', () => {
+    mockGetPatternSlugs.mockReturnValue([])
+    render(<Home />)
+
+    expect(homeMetadata.description).toBe(screen.getByText(/^A collection of emerging patterns/).textContent)
+  })
+
+  it('describes a pattern page with the opening paragraph of the pattern as plain text', async () => {
+    mockGetPatternBySlug.mockReturnValue({
+      title: 'Answer Injection',
+      slug: 'answer-injection',
+      category: 'anti-patterns',
+      content: '## Problem\n\nPutting **the answer** you expect into the [prompt](/x/) makes the model echo it.\n\nSecond paragraph.',
+      rawContent: ''
+    })
+    const params = Promise.resolve({ category: 'anti-patterns', slug: 'answer-injection' })
+
+    expect((await generatePatternMetadata({ params })).description)
+      .toBe('Putting the answer you expect into the prompt makes the model echo it.')
+  })
+
+  it('describes a category page with the intro text it shows', async () => {
+    const params = Promise.resolve({ category: 'obstacles' })
+    render(await CategoryPage({ params: Promise.resolve({ category: 'obstacles' }) }))
+
+    expect((await generateCategoryMetadata({ params })).description)
+      .toBe(screen.getByText(/^Understand the inherent limitations/).textContent)
+  })
+
+  it('describes the contributors page with its intro text', () => {
+    render(<ContributorsPage />)
+
+    expect(contributorsMetadata.description).toBe(screen.getByText(/^Thank you to all the contributors/).textContent)
+  })
+
+  it('describes a contributor page by naming the contributor', async () => {
+    mockGetContributorDetailById.mockReturnValue({ name: 'Ivett Ördög' } as ContributorDetail)
+    const params = Promise.resolve({ authorId: 'ivett_ordog' })
+
+    expect((await generateContributorMetadata({ params })).description).toContain('Ivett Ördög')
+  })
+
+  it('gives the pattern catalog and talk pages distinct descriptions of their own', () => {
+    const descriptions = [homeMetadata, patternCatalogMetadata, talkMetadata].map(m => m.description)
+
+    expect(descriptions.every(Boolean)).toBe(true)
+    expect(new Set(descriptions).size).toBe(descriptions.length)
+  })
+})
+
 describe('Home Page', () => {
   beforeEach(() => {
     mockGetPatternSlugs.mockImplementation((category) => {

website/tests/unit/markdown.test.ts

@@ -1,6 +1,6 @@
 import * as fs from 'fs'
 import * as path from 'path'
-import { getPatternSlugs, getAllPatterns, slugToTitleCase, titleToSlug } from '@/lib/markdown'
+import { getPatternSlugs, getAllPatterns, slugToTitleCase, titleToSlug, extractSummary } from '@/lib/markdown'
 import * as relationships from '@/lib/relationships'
 import { existingPattern } from '../support/existing-pattern'
 
@@ -621,3 +621,24 @@ AI defaults to silent compliance.`
     })
   })
 })
+
+describe('extractSummary', () => {
+  it('summarises with the first real paragraph, skipping a leading related-reading line', () => {
+    const content = [
+      'Closely related: ["Engineer the Harness"](https://example.com/harness)',
+      '',
+      '## Pattern',
+      'Set up automated feedback, give AI permission to iterate.',
+      '',
+      'Later paragraph.',
+    ].join('\n')
+
+    expect(extractSummary(content)).toBe('Set up automated feedback, give AI permission to iterate.')
+  })
+
+  it('keeps an opening paragraph that comes before a related line', () => {
+    const content = 'Names beat descriptions. Always.\n\nRelated: [Catalog](https://example.com/)'
+
+    expect(extractSummary(content)).toBe('Names beat descriptions. Always.')
+  })
+})