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 kostja94/marketing-skills --skill image-optimizationgit clone --depth 1 https://github.com/kostja94/marketing-skillsWrote 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/kostja94/marketing-skills/image-optimization)<a href="https://agentmods.dev/skills/kostja94/marketing-skills/image-optimization"><img src="https://agentmods.dev/badge/skills/kostja94/marketing-skills/image-optimization/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/kostja94/marketing-skills/image-optimization"><img src="https://agentmods.dev/badge/skills/kostja94/marketing-skills/image-optimization.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Socket pass
- Snyk pass
- 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 | $0.00087 | $0.02681 |
| Opus 5 | $0.00044 | $0.01340 |
| Sonnet 5 | $0.00017 | $0.00536 |
| Haiku 4.5 | $0.00009 | $0.00268 |
Grade A, and why
image-optimization 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 6d 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
2 near-identical copies found in the catalogue:
- image-optimization — 100% identical, 0 lines differ
- image-optimization — 100% identical, 0 lines differ
How it starts
The opening of the file, as written. The whole thing — 263 lines — stays where its author put it; the contents beside it link to each section on GitHub.
SEO On-Page: Image Optimization
Guides image optimization for Google Search (text results, Image Pack, Google Images, Discover), Core Web Vitals (LCP), and accessibility. Consolidates image-related best practices from components (hero, trust-badges) and pages (landing-page). References: Google Image SEO, Semrush Image SEO.
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.
Scope
- Discovery & indexing: HTML img elements, image sitemap
- Format & performance: WebP, responsive images, lazy loading, LCP; full CWV optimization in core-web-vitals
- Metadata: Alt text, file names, captions
- Preferred image: primaryImageOfPage, og:image; thumbnail next to title/description in search results
- Structured data: ImageObject, image in Article/Product/etc.
Initial Assessment
Check for project context first: If .claude/project-context.md or .cursor/project-context.md exists, read it for brand and page context.
Identify:
- Context: Hero, content page, product, trust badge, social preview
- Above vs below fold: LCP candidate (hero) vs lazy-loadable
- Image count: Single hero vs gallery, programmatic pages
1. Discovery & Indexing
Use HTML Image Elements
Google finds images in the src attribute of <img> (including inside <picture>). CSS background images are not indexed.
| Do | Don't |
|---|---|
<img src="puppy.jpg" alt="Golden retriever puppy" /> |
<div style="background-image:url(puppy.jpg)"> |
Image Sitemap
Submit an image sitemap to help Google discover images it might otherwise miss. Image sitemaps can include URLs from CDNs (other domains); verify CDN domain in Search Console for crawl error reporting.
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.
- 6d ago First seen · 263 lines · 87 tokens per session scan A 4a410b72a2f2
image-optimization is a skill published in the GitHub repository kostja94/marketing-skills (960 stars, last pushed 3mo ago), licensed MIT. It adds 87 tokens to every session and 2,681 once invoked, about $0.0004 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 2026-09-03.
Other skills, from other repositories
landing-page-generator
Generates high-converting Next.js/React landing pages with Tailwind CSS. Uses PAS, AIDA, and BAB frameworks for optimized copy/components (Heroes, Features, Pricing). Focuses on Core Web Vitals/SEO.
animate
Review a feature and enhance it with purposeful animations, micro-interactions, and motion effects that improve usability and delight. Use when the user mentions adding animation, transitions, micro-interactions, motion design, hover effects, or making the UI feel more alive.
audit
Run technical quality checks across accessibility, performance, theming, responsive design, and anti-patterns. Generates a scored report with P0-P3 severity ratings and actionable plan. Use when the user wants an accessibility check, performance audit, or technical quality review.
adapt
Adapt designs to work across different screen sizes, devices, contexts, or platforms. Implements breakpoints, fluid layouts, and touch targets. Use when the user mentions responsive design, mobile layouts, breakpoints, viewport adaptation, or cross-device compatibility.
Dark Mode Bug Finder
Detect dark mode rendering issues including contrast failures, missing theme tokens, image inversions, and transition glitches across components.
taste-skill
Anti-slop frontend skill for landing pages, portfolios, and redesigns. The agent reads the brief, infers the right design direction, and ships interfaces that do not look templated. Real design systems when applicable, audit-first on redesigns, strict pre-flight check.