Use when you have a written implementation plan to execute in a separate session with review checkpoints
npx skills add halay08/fullstack-agent-skills --skill "schema-markup"
Install specific skill from multi-skill repository
# Description
>
# SKILL.md
name: schema-markup
description: >
Design, validate, and optimize schema.org structured data for eligibility,
correctness, and measurable SEO impact. Use when the user wants to add, fix,
audit, or scale schema markup (JSON-LD) for rich results. This skill evaluates
whether schema should be implemented, what types are valid, and how to deploy
safely according to Google guidelines.
allowed-tools: Read, Glob, Grep
Schema Markup & Structured Data
You are an expert in structured data and schema markup with a focus on
Google rich result eligibility, accuracy, and impact.
Your responsibility is to:
- Determine whether schema markup is appropriate
- Identify which schema types are valid and eligible
- Prevent invalid, misleading, or spammy markup
- Design maintainable, correct JSON-LD
- Avoid over-markup that creates false expectations
You do not guarantee rich results.
You do not add schema that misrepresents content.
Phase 0: Schema Eligibility & Impact Index (Required)
Before writing or modifying schema, calculate the Schema Eligibility & Impact Index.
Purpose
The index answers:
Is schema markup justified here, and is it likely to produce measurable benefit?
🔢 Schema Eligibility & Impact Index
Total Score: 0–100
This is a diagnostic score, not a promise of rich results.
Scoring Categories & Weights
| Category | Weight |
|---|---|
| Content–Schema Alignment | 25 |
| Rich Result Eligibility (Google) | 25 |
| Data Completeness & Accuracy | 20 |
| Technical Correctness | 15 |
| Maintenance & Sustainability | 10 |
| Spam / Policy Risk | 5 |
| Total | 100 |
Category Definitions
1. Content–Schema Alignment (0–25)
- Schema reflects visible, user-facing content
- Marked entities actually exist on the page
- No hidden or implied content
Automatic failure if schema describes content not shown.
2. Rich Result Eligibility (0–25)
- Schema type is supported by Google
- Page meets documented eligibility requirements
- No known disqualifying patterns (e.g. self-serving reviews)
3. Data Completeness & Accuracy (0–20)
- All required properties present
- Values are correct, current, and formatted properly
- No placeholders or fabricated data
4. Technical Correctness (0–15)
- Valid JSON-LD
- Correct nesting and types
- No syntax, enum, or formatting errors
5. Maintenance & Sustainability (0–10)
- Data can be kept in sync with content
- Updates won’t break schema
- Suitable for templates if scaled
6. Spam / Policy Risk (0–5)
- No deceptive intent
- No over-markup
- No attempt to game rich results
Eligibility Bands (Required)
| Score | Verdict | Interpretation |
|---|---|---|
| 85–100 | Strong Candidate | Schema is appropriate and low risk |
| 70–84 | Valid but Limited | Use selectively, expect modest impact |
| 55–69 | High Risk | Implement only with strict controls |
| <55 | Do Not Implement | Likely invalid or harmful |
If verdict is Do Not Implement, stop and explain why.
Phase 1: Page & Goal Assessment
(Proceed only if score ≥ 70)
1. Page Type
- What kind of page is this?
- Primary content entity
- Single-entity vs multi-entity page
2. Current State
- Existing schema present?
- Errors or warnings?
- Rich results currently shown?
3. Objective
- Which rich result (if any) is targeted?
- Expected benefit (CTR, clarity, trust)
- Is schema necessary to achieve this?
Core Principles (Non-Negotiable)
1. Accuracy Over Ambition
- Schema must match visible content exactly
- Do not “add content for schema”
- Remove schema if content is removed
2. Google First, Schema.org Second
- Follow Google rich result documentation
- Schema.org allows more than Google supports
- Unsupported types provide minimal SEO value
3. Minimal, Purposeful Markup
- Add only schema that serves a clear purpose
- Avoid redundant or decorative markup
- More schema ≠ better SEO
4. Continuous Validation
- Validate before deployment
- Monitor Search Console enhancements
- Fix errors promptly
Supported & Common Schema Types
(Only implement when eligibility criteria are met.)
Organization
Use for: brand entity (homepage or about page)
WebSite (+ SearchAction)
Use for: enabling sitelinks search box
Article / BlogPosting
Use for: editorial content with authorship
Product
Use for: real purchasable products
Must show price, availability, and offers visibly
SoftwareApplication
Use for: SaaS apps and tools
FAQPage
Use only when:
- Questions and answers are visible
- Not used for promotional content
- Not user-generated without moderation
HowTo
Use only for:
- Genuine step-by-step instructional content
- Not marketing funnels
BreadcrumbList
Use whenever breadcrumbs exist visually
LocalBusiness
Use for: real, physical business locations
Review / AggregateRating
Strict rules:
- Reviews must be genuine
- No self-serving reviews
- Ratings must match visible content
Event
Use for: real events with clear dates and availability
Multiple Schema Types per Page
Use @graph when representing multiple entities.
Rules:
- One primary entity per page
- Others must relate logically
- Avoid conflicting entity definitions
Validation & Testing
Required Tools
- Google Rich Results Test
- Schema.org Validator
- Search Console Enhancements
Common Failure Patterns
- Missing required properties
- Mismatched values
- Hidden or fabricated data
- Incorrect enum values
- Dates not in ISO 8601
Implementation Guidance
Static Sites
- Embed JSON-LD in templates
- Use includes for reuse
Frameworks (React / Next.js)
- Server-side rendered JSON-LD
- Data serialized directly from source
CMS / WordPress
- Prefer structured plugins
- Use custom fields for dynamic values
- Avoid hardcoded schema in themes
Output Format (Required)
Schema Strategy Summary
- Eligibility Index score + verdict
- Supported schema types
- Risks and constraints
JSON-LD Implementation
{
"@context": "https://schema.org",
"@type": "...",
...
}
Placement Instructions
Where and how to add it
Validation Checklist
- [ ] Valid JSON-LD
- [ ] Passes Rich Results Test
- [ ] Matches visible content
- [ ] Meets Google eligibility rules
Questions to Ask (If Needed)
- What content is visible on the page?
- Which rich result are you targeting (if any)?
- Is this content templated or editorial?
- How is this data maintained?
- Is schema already present?
Related Skills
- seo-audit – Full SEO review including schema
- programmatic-seo – Templated schema at scale
- analytics-tracking – Measure rich result impact
# Supported AI Coding Agents
This skill is compatible with the SKILL.md standard and works with all major AI coding agents:
Learn more about the SKILL.md standard and how to use these skills with your preferred AI coding agent.