schema-markup

schema-markup is a skill for Claude Code, Codex from T4wroot/agentic-seo. It costs 181 tokens per session (4,788 once invoked), scanned A, a copy of schema-markup, MIT.

A guide for improving images for search visibility, page speed, and accessibility.

In plain words
What is it for?
Use it to review alt text, filenames, captions, formats such as WebP, responsive images, lazy loading, image sitemaps, and image structured data.
Why use it?
It helps reduce image-related performance problems, make images understandable to screen readers, and improve how search engines find them.

Skill for Claude CodeCodex

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

Good fit Use it to review alt text, filenames, captions, formats such as WebP, responsive images, lazy loading, image sitemaps, and image structured data.

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Install with agentmods
npx agentmods add skills/t4wroot/agentic-seo/schema
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 T4wroot/agentic-seo --skill schema
Clone the repo
git clone --depth 1 https://github.com/T4wroot/agentic-seo

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 schema-markup

README.md
[![agentmods](https://agentmods.dev/badge/skills/t4wroot/agentic-seo/schema/github.svg)](https://agentmods.dev/skills/t4wroot/agentic-seo/schema)
Your own site
<a href="https://agentmods.dev/skills/t4wroot/agentic-seo/schema"><img src="https://agentmods.dev/badge/skills/t4wroot/agentic-seo/schema/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 schema-markup

Your own site · 80×15
<a href="https://agentmods.dev/skills/t4wroot/agentic-seo/schema"><img src="https://agentmods.dev/badge/skills/t4wroot/agentic-seo/schema.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 181 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,788 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.
Origin 100% copy Near-identical to another mod 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 $0.00181 $0.04788
Opus 5 $0.00090 $0.02394
Sonnet 5 $0.00036 $0.00958
Haiku 4.5 $0.00018 $0.00479

Measured 7d ago against content hash 78262fdc41f5, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

schema-markup 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

This is a copy

100% identical to schema-markup — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

skills/seo/on-page/schema/SKILL.md · 321 lines

How it starts

The opening of the file, as written. The whole thing — 321 lines — stays where its author put it; the contents beside it link to each section on GitHub.

SEO On-Page: Schema / Structured Data

Guides implementation of Schema.org structured data (JSON-LD) for rich snippets, enhanced search results, and Generative Engine Optimization (GEO).

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 (On-Page SEO)

  • Schema markup: Schema.org types for rich results, AI search visibility, and machine-readable content
  • Schema.org vs. search engines: Schema.org defines 800+ types; each search engine supports only a subset for rich results

Schema.org vs. Search Engine Support

Schema.org and Google Structured Data are not fully aligned. Schema.org is an open vocabulary (800+ types); Google, Bing, and other engines each support only a curated subset for rich results.

Engine Support Notes
Google Subset only Only types in Google's search gallery generate rich results. Valid Schema.org markup not in Google's list won't produce enhanced snippets—even if technically correct.
Bing Subset; different Supports JSON-LD, Microdata, RDFa, Open Graph. Some types (e.g., Product, Offer) have format-specific support. Check Bing Webmaster docs.
Other engines Varies Yandex, DuckDuckGo, AI search tools (Perplexity, etc.) may use Schema.org for understanding even when they don't display rich results.

Practical implication: Implement Schema.org markup for your content type. If Google doesn't show rich results for that type, Bing or AI systems may still use it. Always verify against Google's developer docs for Google-specific rich result eligibility.

Rich Results: Google Support (2026)

Read the full file on GitHub · 321 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 · 321 lines · 181 tokens per session scan A 78262fdc41f5

Subscribe to this mod's changes

schema-markup is a skill published in the GitHub repository T4wroot/agentic-seo (15 stars, last pushed 8d ago), licensed MIT. It adds 181 tokens to every session and 4,788 once invoked, about $0.0009 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to schema-markup, differing in 0 lines, and is treated as a copy.