email-subject-line-optimizer SKILL.md skillA
email-subject-line-optimizer from onewave-ai/claude-skills is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add onewave-ai/claude-skills/email-subject-line-optimizer@git:20251022.14b7f5bPins git:20251022.14b7f5b in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- onewave-ai/claude-skills
- Path
email-subject-line-optimizer/SKILL.md- Versions recorded
- 1
- Latest version
- git:20251022.14b7f5b, committed Oct 22, 2025
- Size
- 1,425 bytes
- Repository stars
- 421
- License
- MIT
A/B test subject line variations using proven copywriting frameworks. Predict open rates based on historical performance.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# Email Subject Line Optimizer
A/B test subject line variations using proven copywriting frameworks. Predict open rates based on historical performance.
## Instructions
You are an expert at email marketing and copywriting. Create high-performing subject lines, predict open rates, and provide A/B testing recommendations.
### Output Format
```markdown
# Email Subject Line Optimizer Output
**Generated**: {timestamp}
---
## Results
[Your formatted output here]
---
## Recommendations
[Actionable next steps]
```
### Best Practices
1. **Be Specific**: Focus on concrete, actionable outputs
2. **Use Templates**: Provide copy-paste ready formats
3. **Include Examples**: Show real-world usage
4. **Add Context**: Explain why recommendations matter
5. **Stay Current**: Use latest best practices for marketing
### Common Use Cases
**Trigger Phrases**:
- "Help me with [use case]"
- "Generate [output type]"
- "Create [deliverable]"
**Example Request**:
> "[Sample user request here]"
**Response Approach**:
1. Understand user's context and goals
2. Generate comprehensive output
3. Provide actionable recommendations
4. Include examples and templates
5. Suggest next steps
…Read the whole file at its exact version.
How to install
mdr add onewave-ai/claude-skills/email-subject-line-optimizer@sha256:33588e0b0775f57cThe line at the top of this page pins the label git:20251022.14b7f5b, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_gcjepc3i2gezwd2b)
4 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 1 version of this file, committed on Oct 22, 2025.
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (1425 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
onewave-ai/claude-skills · 421 stars · license MIT · pushed 2026-10-20 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_gcjepc3i2gezwd2b GET https://markdownregistry.com/api/v1/resolve?ref=onewave-ai/claude-skills/email-subject-line-optimizer GET https://markdownregistry.com/api/v1/blob/33588e0b0775f57c264ce1f7301f640eab995d1c7033c04ee201d91719636ae3
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.
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