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Image Optimization Analysis · sickn33 | DecimalAI

marketingby sickn33

Image Optimization Analysis

sickn33/seo-images

Source sickn33/agentic-awesome-skills ↗License MIT

Image optimization analysis for SEO and performance. Checks alt text, file sizes, formats, responsive images, lazy loading, and CLS prevention.

SkillScore86Maintained

Automatic

Marketing & Content pack

Last verified 8/11/2026

What it changes

Passed 19 of 22 test cases with the skill, and 12 of 22 without it.

Without skill55%

With skill86%

Checks it passed that the model alone missed

The audit flags hero banner images over 300KB as warnings.
The audit flags content images exceeding 200KB as warnings.
The audit flags hero banner images over 700KB as critical issues.

and 6 more in the full report

7 fixed12 passed either way3 still failing0 broke

Pass-rate lift: +32 pp
Tokens: +73%
Agent turns: 0%
Response time: -11%

Model gemini-3.6-flashMeasured 8/11/2026v119 of 22 cases passed with skill

Tokens, turns and time describe resource use, not a dollar price.

Use this skill

Save it into your project's skills folder. Claude Code picks it up in its next session.

curl -fsSL --create-dirs -o .claude/skills/sickn33-seo-images/SKILL.md https://app.decimal.ai/s/sickn33-seo-images/SKILL.md

Want it pinned and updatable? pip install "decimalai>=0.15", then decimalai skills add sickn33-seo-images, and start Claude Code with claude --plugin-dir "$(git rev-parse --show-toplevel)/.agents"

1 · One-time — install the CLI (docs ↗)

pip install "decimalai>=0.15"

2 · Get the skill — writes .agents/skills/sickn33-seo-images/ and pins it in .decimal/skills.lock

decimalai skills add sickn33-seo-images

No CLI? Get the same file — curl · raw file

curl -fsSL --create-dirs -o .claude/skills/sickn33-seo-images/SKILL.md https://app.decimal.ai/s/sickn33-seo-images/SKILL.md

Raw file: /s/sickn33-seo-images/SKILL.md ↗ · machine-readable summary at /s/sickn33-seo-images.json ↗

Safety checks: 3 of 3 passed

Code scan CleanIntent PassedContent Clean

See it in action

One of 7 test cases the skill fixed. Same model, same prompt, with and without the skill.

1 of 7

Prompt

What non-blocking image attribute should be added to below-the-fold content images to prevent image decoding from freezing the browser main thread?

What was checked, without and with the skill
Checked	Without skill	With skill
The recommendation specifies adding decoding="async" to non-LCP images.	Missed	Passed

case-09 · gemini-3.6-flash · 8/11/2026 · answers are capped and redacted

What's inside

The instructions your model reads when the skill loads.

SKILL.md177 linessingle file

Image Optimization Analysis

When to Use

Use when auditing image SEO, alt text, file sizes, formats, or lazy loading.
Use when the user wants image-specific performance recommendations.
Use when checking media quality signals that affect both SEO and Core Web Vitals.

Checks

Alt Text

Present on all <img> elements (except decorative: role="presentation")
Descriptive: describes the image content, not "image.jpg" or "photo"
Includes relevant keywords where natural, not keyword-stuffed
Length: 10-125 characters

Good examples:

"Professional plumber repairing kitchen sink faucet"
"Red 2024 Toyota Camry sedan front view"
"Team meeting in modern office conference room"

Bad examples:

"image.jpg" (filename, not description)
"plumber plumbing plumber services" (keyword stuffing)
"Click here" (not descriptive)

File Size

Tiered thresholds by image category:

Image Category	Target	Warning	Critical
Thumbnails	< 50KB	> 100KB	> 200KB
Content images	< 100KB	> 200KB	> 500KB
Hero/banner images	< 200KB	> 300KB	> 700KB

Recommend compression to target thresholds where possible without quality loss.

Format

Format	Browser Support	Use Case

Track record

Benchmark

19 / 22

test cases passed, vs 12 / 22 without

Adoption

Users: 0
Times used: 0

Safety and source details

SkillSafety

✓ 3 of 3 passed

Code scan15 of 15 checks clean

0 critical · 0 warning · 0 info — scanner v4 — 8/3/2026

View 15 scanner checks

live_secretremote_code_executionreverse_shelldata_exfiltrationssrf_metadataagent_snoopinganti_refusaldestructive_commandsobfuscated_unicodeunicode_homoglyphopaque_blobsuspicious_urltool_overreachtrigger_abuseprompt_injection_phrasing

IntentSafe

LLM judge · does the skill do what it claims

ContentClean

LLM judge · policy & harmful-content review

Source

Imported

sickn33 / agentic-awesome-skills

skills/seo-images/SKILL.md

View on GitHub ↗

License MITImported 8/3/2026Version v1

Other skills for the same job

Published skills whose descriptions closely match this one, with their headline benchmark lift.

More skills from the same source and nearby in the registry, with their headline benchmark lift.

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See it in action

What's inside

Image Optimization Analysis

When to Use

Checks

Alt Text

File Size

Format

Track record

Benchmark

Adoption

SkillSafety

Source

Other skills for the same job

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