mobile-friendly

mobile-friendly is a skill for Claude Code, Codex from kostja94/marketing-skills. It costs 81 tokens per session (1,392 once invoked), scanned A, original, MIT.

A guide to making websites work well on phones and supporting mobile-first indexing, where Google primarily evaluates the mobile version of a page. It covers responsive layouts, viewports, readable text, touch targets, and matching mobile and desktop content.

In plain words
What is it for?
Use it to check responsive design, viewport settings, mobile content parity, font sizes, touch targets, intrusive pop-ups, and reports from Search Console's mobile usability tools.
Why use it?
It helps prevent mobile usability problems and ensures that important content is available on the version Google uses for indexing and ranking. It also explains when Accelerated Mobile Pages may matter.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

not rated 963repo +13 3mo ago A scan Socket: passSnyk: passSkillSpector: pass 81 tokens original MIT

Good fit Use it to check responsive design, viewport settings, mobile content parity, font sizes, touch targets, intrusive pop-ups, and reports from Search Console's mobile usability tools.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/kostja94/marketing-skills/mobile-friendly
Install

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.

Any agent
npx skills add kostja94/marketing-skills --skill mobile-friendly
Clone the repo
git clone --depth 1 https://github.com/kostja94/marketing-skills

Made for: Claude Code, Codex.

Wrote 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.

agentmods badge for mobile-friendly

README.md
[![agentmods](https://agentmods.dev/badge/skills/kostja94/marketing-skills/mobile-friendly/github.svg)](https://agentmods.dev/skills/kostja94/marketing-skills/mobile-friendly)
Your own site
<a href="https://agentmods.dev/skills/kostja94/marketing-skills/mobile-friendly"><img src="https://agentmods.dev/badge/skills/kostja94/marketing-skills/mobile-friendly/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.

agentmods 80×15 button for mobile-friendly

Your own site · 80×15
<a href="https://agentmods.dev/skills/kostja94/marketing-skills/mobile-friendly"><img src="https://agentmods.dev/badge/skills/kostja94/marketing-skills/mobile-friendly.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 81 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,392 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • Socket pass 9 Apr 2026
  • Snyk pass 9 Apr 2026
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00081 $0.01392
Opus 5 $0.00041 $0.00696
Sonnet 5 $0.00016 $0.00278
Haiku 4.5 $0.00008 $0.00139

Measured 7d ago against content hash 6e0b7ed5547c, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

mobile-friendly 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 7d 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.

Origin

Copies of this mod

2 near-identical copies found in the catalogue:

skills/seo/technical/mobile-friendly/SKILL.md · 124 lines

How it starts

The opening of the file, as written. The whole thing — 124 lines — stays where its author put it; the contents beside it link to each section on GitHub.

SEO Technical: Mobile-Friendly

Guides mobile-first indexing optimization and mobile usability. Google uses the mobile version of pages for indexing and ranking; mobile-friendliness is a ranking factor.

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 (Technical SEO)

  • Mobile-first indexing: Google primarily crawls and indexes mobile version
  • Mobile adaptation: Responsive design, viewport, breakpoints
  • Content parity: Mobile and desktop content should match (or mobile preferred)
  • Mobile usability: Viewport, font size, touch targets, no intrusive interstitials
  • AMP: Accelerated Mobile Pages—status and when to consider

Initial Assessment

Check for project context first: If .claude/project-context.md or .cursor/project-context.md exists, read it for site URL.

Identify:

  1. Site type: Responsive, separate AMP, dynamic serving
  2. Content parity: Does mobile show same content as desktop?
  3. Tools: GSC Mobile Usability report; Mobile-Friendly Test

Mobile-First Indexing Requirements

Requirement Action
Content parity Mobile version must include same primary content as desktop; avoid hiding key content on mobile
Structured data Same schema on mobile and desktop; ensure mobile URLs in schema
Metadata Same title, meta description on mobile
Media Images should be crawlable; avoid lazy-loading above-fold images

Responsive Design & Mobile Adaptation

Responsive design = Single HTML; CSS media queries adapt layout to screen size. Preferred for SEO: one URL, no duplicate content.

Principle Practice
Mobile-first Design for mobile first; enhance for desktop
Fluid layout Use %, vw, flex, grid; avoid fixed pixel widths
Breakpoints Common: 320px, 768px, 1024px, 1280px; match device widths
Images Responsive images (srcset, sizes); see image-optimization

Read the full file on GitHub · 124 lines

Changes

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.

  1. 7d ago First seen · 124 lines · 81 tokens per session scan A 6e0b7ed5547c

Subscribe to this mod's changes

mobile-friendly is a skill published in the GitHub repository kostja94/marketing-skills (963 stars, last pushed 3mo ago), licensed MIT. It adds 81 tokens to every session and 1,392 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.

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