AG Kit is a toolkit that gives Google Antigravity coding agents a structured workspace with rules, skills, specialist agents, workflows, persistent memory, orchestration, MCP guidance, and a safety hook. It is for building and operating agent workflows in Antigravity, and its catalogue entries provide parts of that workspace contract.
Borrowing it
Nothing to install: this file belongs to vudovn/ag-kit. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/vudovn/ag-kit/main/.agents/skills/seo-fundamentals/SKILL.mdgit clone --depth 1 https://github.com/vudovn/ag-kitWrote 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/vudovn/ag-kit/seo-fundamentals)<a href="https://agentmods.dev/skills/vudovn/ag-kit/seo-fundamentals"><img src="https://agentmods.dev/badge/skills/vudovn/ag-kit/seo-fundamentals/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/vudovn/ag-kit/seo-fundamentals"><img src="https://agentmods.dev/badge/skills/vudovn/ag-kit/seo-fundamentals.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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 | $0.00024 | $0.00719 |
| Opus 5 | $0.00012 | $0.00360 |
| Sonnet 5 | $0.00005 | $0.00144 |
| Haiku 4.5 | $0.00002 | $0.00072 |
Grade A, and why
seo-fundamentals 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 12d ago.
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.
Copies of this mod
7 near-identical copies found in the catalogue:
- seo-fundamentals — 91% identical, 9 lines differ
- seo-fundamentals — 88% identical, 3 lines differ
- seo-fundamentals — 86% identical, 2 lines differ
- seo-fundamentals — 86% identical, 2 lines differ
- seo-fundamentals — 86% identical, 2 lines differ
- seo-fundamentals — 86% identical, 2 lines differ
- seo-fundamentals — 86% identical, 2 lines differ
How it starts
The opening of the file, as written. The whole thing — 132 lines — stays where its author put it; the contents beside it link to each section on GitHub.
SEO Fundamentals
Principles for search engine visibility.
1. E-E-A-T Framework
| Principle | Signals |
|---|---|
| Experience | First-hand knowledge, real examples |
| Expertise | Credentials, depth of knowledge |
| Authoritativeness | Backlinks, mentions, industry recognition |
| Trustworthiness | HTTPS, transparency, accurate info |
2. Core Web Vitals
| Metric | Target | Measures |
|---|---|---|
| LCP | < 2.5s | Loading performance |
| INP | < 200ms | Interactivity |
| CLS | < 0.1 | Visual stability |
3. Technical SEO Principles
Site Structure
| Element | Purpose |
|---|---|
| XML sitemap | Help crawling |
| robots.txt | Control access |
| Canonical tags | Prevent duplicates |
| HTTPS | Security signal |
Performance
| Factor | Impact |
|---|---|
| Page speed | Core Web Vital |
| Mobile-friendly | Ranking factor |
| Clean URLs | Crawlability |
4. Content SEO Principles
Page Elements
| Element | Best Practice |
|---|---|
| Title tag | 50-60 chars, keyword front |
| Meta description | 150-160 chars, compelling |
| H1 | One per page, main keyword |
| H2-H6 | Logical hierarchy |
| Alt text | Descriptive, not stuffed |
Content Quality
| Factor | Importance |
|---|---|
| Depth | Comprehensive coverage |
| Freshness | Regular updates |
| Uniqueness | Original value |
| Readability | Clear writing |
5. Schema Markup Types
| Type | Use |
|---|---|
| Article | Blog posts, news |
| Organization | Company info |
| Person | Author profiles |
| FAQPage | Q&A content |
| Product | E-commerce |
| Review | Ratings |
| BreadcrumbList | Navigation |
6. AI Content Guidelines
What Google Looks For
| ✅ Do | ❌ Don't |
|---|---|
| AI draft + human edit | Publish raw AI content |
| Add original insights | Copy without value |
| Expert review | Skip fact-checking |
| Follow E-E-A-T | Keyword stuffing |
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 12d ago First seen · 132 lines · 24 tokens per session scan A 4ab2efde333c
seo-fundamentals is a skill published in the GitHub repository vudovn/ag-kit (8,174 stars, last pushed 5d ago), licensed MIT. It adds 24 tokens to every session and 719 once invoked, about $0.0001 per session on Opus 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 2026-08-30.
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