Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add dalroot/agentic-seo --skill 404git clone --depth 1 https://github.com/dalroot/agentic-seoWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/dalroot/agentic-seo/404)<a href="https://agentmods.dev/skills/dalroot/agentic-seo/404"><img src="https://agentmods.dev/badge/skills/dalroot/agentic-seo/404/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/dalroot/agentic-seo/404"><img src="https://agentmods.dev/badge/skills/dalroot/agentic-seo/404.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00082 | $0.00676 |
| Opus 5.5 | $0.00033 | $0.00270 |
| Sonnet 5.5 | $0.00016 | $0.00135 |
| Haiku 4.5 | $0.00008 | $0.00068 |
Grade A, and why
404-page-generator scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured today.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 74 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Pages: 404 Error Page
Guides 404 error page design for UX, conversion recovery, and brand consistency.
When invoking: On first use, if helpful, open with 1-2 sentences on what this skill covers and why it matters, then provide the main output. On subsequent use or when the user asks to skip, go directly to the main output.
Initial Assessment
Check for project context first: If .claude/project-context.md or .cursor/project-context.md exists, read it for brand voice, key pages, and Section 12 (Visual Identity).
Identify:
- Site structure: Key pages to link (homepage, popular pages, search)
- Brand tone: Friendly, professional, playful
- Conversion goal: Recover lost visitors, drive to key pages
Best Practices
Clear Error Messaging
- User-friendly: Neutral message explaining the page wasn't found
- Optional 404 display: Can show "404" but avoid blaming the user
- Empathetic tone: Acknowledge the error gracefully; turn frustration into opportunity
Navigation and Redirection
| Element | Purpose |
|---|---|
| Site navigation | Header/footer so users know they're still on your site |
| Search | Help users find what they need |
| Popular pages | Links to homepage, features, pricing, blog |
| Similar URLs | Suggest corrections for common typos |
| Avoid auto-redirect | Unless confident of user intent |
Design and Branding
- Consistent design: Same header, footer, colors as rest of site (brand-visual-generator)
- Avoid confusion: Users should not think they've left your domain
- Mobile responsive: Test on all devices
Conversion Opportunities
404 pages can drive conversions by:
- Showcasing popular products or features
- Featuring testimonials or social proof
- Offering special promotions or value
- Linking to mobile app or newsletter
Technical
- Track 404s: Monitor broken links, fix or redirect
- Accessibility: Maintain WCAG standards
- HTTP status: Ensure proper 404 response code
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- today First seen · 74 lines · 82 tokens per session scan A cde007e2e506
404-page-generator is a skill published in the GitHub repository dalroot/agentic-seo (25 stars, last pushed 6d ago), licensed MIT. It adds 82 tokens to every session and 676 once invoked, about $0.0003 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-10-26.
Other skills, from other repositories
brand-visual-generator
When the user wants to define, audit, or apply visual identity (typography, colors, spacing, design tokens, frontend aesthetics). Also use when the user mentions "brand style guide," "visual identity," "design system," "typography," "color palette," "brand guidelines," "AI brand aesthetics," "brand colors," "font…
breadcrumb-generator
When the user wants to add, optimize, or audit breadcrumb navigation. Also use when the user mentions "breadcrumbs," "breadcrumb trail," "breadcrumb nav," "breadcrumb links," "path navigation," "site breadcrumb," "BreadcrumbList schema," "location-based breadcrumb," "attribute-based breadcrumb," "site hierarchy…
favicon-generator
When the user wants to implement, optimize, or audit favicon and app icons. Also use when the user mentions "favicon," "app icon," "browser icon," "touch icon," "PWA icon," "favicon sizes," "apple-touch-icon," "favicon.ico," "site icon," or "tab icon." For visual system, use brand-visual-generator.
comparison-table-generator
When the user wants to create, optimize, or audit a comparison table section—an in-page block (HTML table or responsive equivalent) comparing products, methods, or approaches, with optional supporting copy. Also use when the user mentions "comparison table," "compare table," "feature matrix," "vs table," "side-by-side…
branding
When the user wants to define, audit, or apply brand strategy—purpose, values, positioning, storytelling, voice, narrative (not only visuals). Also use when the user mentions "brand strategy," "brand story," "brand storytelling," "brand voice," "brand identity," "brand guidelines," "brand purpose," "brand values,"…
hero-generator
When the user wants to design, optimize, or audit hero sections (above-the-fold main visual area). Also use when the user mentions "hero," "hero section," "hero area," "above the fold," "above the fold content," "landing hero," "main banner," "banner section," "first fold," "hero section design," "hero conversion,"…