Skills subject-line-lab

📦

subject-line-lab

Name: subject-line-lab
Author: aaron-he-zhu

v19.0.0 Content revision r2 Safe 📁 Filesystem access⚙️ External commands🌐 Network access

Create Test-Ready Email Subject Lines

Weak subject lines can waste email test cells and obscure a useful offer. This skill creates and ranks subject and preheader variants with clear heuristic flags before a campaign test.

Supports: Claude Codex Code(CC)

🥉 78 Bronze

Install with my Agent

Copy this request to your Agent. It includes the canonical Skill page and manifest.

Agent request

Review the Skillstore skill "subject-line-lab" from https://skillstore.io/skills/aaron-he-zhu-subject-line-lab.md and its manifest at https://skillstore.io/api/skills/aaron-he-zhu-subject-line-lab/manifest. Verify the artifact. You may proceed after verification, subject to the environment's own policy.

Your Agent should still show its plan and request any confirmation required by the security policy.

Agent-readable resources

Use these links when an AI agent, crawler, or script needs clean context instead of reading the full page.

Markdown detail GET /skills/aaron-he-zhu-subject-line-lab.md Signed manifest GET /api/skills/aaron-he-zhu-subject-line-lab/manifest Signed lockfile GET /api/skills/aaron-he-zhu-subject-line-lab/lockfile

Test it

Using "subject-line-lab". Generate options for a summer course discount in promo mode.

Expected outcome:

SUBJ-A — Benefit: Build job-ready skills this summer
Preheader: Choose a course and start learning this week.
Rank: Advance SUBJ-A. The promise appears before the estimated mobile cutoff.

Using "subject-line-lab". Pre-score: FINAL HOURS!!! Save 50% now 💥💥

Expected outcome:

Flag: Exclamation stacking and multiple emojis.
Flag: The urgency and discount require user-provided support.
Recommendation: Cut or revise before testing.

Security Audit

Safe

v6 • 7/27/2026 Open versioned report

All 53 static detections are false positives caused by Markdown code spans and relative documentation links. The skill gives local email-writing guidance, labels heuristics as estimates, treats imported material as untrusted, and requires confirmation before saving memory. No prompt injection, data exfiltration, command execution, or unsafe filesystem behavior was found.

Files scanned

126

Lines analyzed

Review items

False positives ignored

Risk Factors

📁 Filesystem access (25)

⚙️ External commands (20)

🌐 Network access (2)

SKILL.md:10 SKILL.md:13

No confirmed security findings were detected by the latest completed static and semantic audit. This does not prove the skill has no side effects.

Audited by: claude View Audit History →

Share & cite this report

Share the versioned assessment report, neutral badge, embed card, and citations. Skillstore reports evidence without deciding whether this Skill is safe.

Open versioned report

Copy report link

https://skillstore.io/skills/aaron-he-zhu-subject-line-lab/audits/6?utm_source=security_passport&utm_medium=share&utm_campaign=versioned_report

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Academic citations (APA · BibTeX · CFF)

APA citation

aaron-he-zhu. (2026). subject-line-lab security audit report (audit version 6) [Author version 19.0.0]. Skillstore. https://skillstore.io/skills/aaron-he-zhu-subject-line-lab/audits/6

BibTeX citation

@techreport{aaron-he-zhu-aaron-he-zhu-subject-line-lab-2026,
  author = {aaron-he-zhu},
  title = {subject-line-lab security audit report (audit version 6)},
  institution = {Skillstore},
  year = {2026},
  number = {6},
  url = {https://skillstore.io/skills/aaron-he-zhu-subject-line-lab/audits/6},
  note = {Author version 19.0.0}
}

CITATION.cff

cff-version: 1.2.0
message: "If you use this Skill, cite its author and this versioned security audit report."
title: "subject-line-lab security audit report (audit version 6)"
version: "19.0.0"
type: report
authors:
  - name: "aaron-he-zhu"
date-released: "2026-07-27"
url: "https://skillstore.io/skills/aaron-he-zhu-subject-line-lab/audits/6"
identifiers:
  - type: other
    value: "skillstore:aaron-he-zhu-subject-line-lab:audit:6"
    description: "Skillstore immutable audit report identifier"

Skillstore Score

Why this score Evidence Confidence: Medium

Architecture

100

Maintainability

Content

Community

100

Spec Compliance

What You Can Build

Prepare a promotion test

Create and rank subject and preheader options before a promotional campaign test.

Review cold outreach

Check B2B outreach subjects for truncation, emoji use, and misleading patterns.

Improve a newsletter launch

Compare newsletter subject options and preview the recipient inbox view.

Try These Prompts

Check one subject line

Pre-score this subject line and preheader for a newsletter: [subject] / [preheader]. From-name: [name].

Generate promotion options

Generate five subject-line and preheader variants for [offer] in promo mode. Use from-name [name] and rank them by heuristic pre-score.

Review candidate list

Pre-score these six subject lines for desktop and mobile truncation, spam patterns, emoji count, and inbox preview. Mode: [promo or cold]. From-name: [name]. Candidates: [list].

Create a test-ready shortlist

Generate eight distinct subject and preheader variants for [offer]. Use [promo, cold, or newsletter] mode. Mark measured and estimated checks, cut weak options, and provide a ranked shortlist for an A/B test.

Best Practices

Provide the offer, audience, mode, and from-name before generating variants.
Treat spam and truncation results as estimates, then validate with campaign results.
Use one variable per test cell after selecting the ranked shortlist.

Avoid

Do not present a clean heuristic pre-score as an inbox-placement guarantee.
Do not invent discounts, statistics, scarcity, or personalization claims.
Do not use this skill as a substitute for body-copy review or full deliverability testing.

Frequently Asked Questions

Does this skill guarantee inbox placement?

No. It flags common subject-level patterns but cannot predict Gmail, Outlook, or other provider decisions.

Can it write email body copy?

No. It focuses on subject lines and preheaders only.

How many variants does it create?

It creates three to eight variants when generating from an offer or angle.

Can I use past campaign data?

Yes. Provide a manual export to inform angle and length choices. Treat results as context, not proof.

Does it support cold outreach?

Yes. It applies stricter emoji guidance for B2B cold-outbound mode.

What should I do after selecting variants?

Use an email experiment design process to test the surviving variants with controlled variables.

Developer Details

Author

aaron-he-zhu

License

Apache-2.0

Author version

v19.0.0

Skillstore revision

Repository

https://github.com/aaron-he-zhu/aaron-marketing-skills/tree/main/email/engage/subject-line-lab

Ref

0715a6e09ea875c8e28cb705ce87cc83045e69c1

Maintenance freshness

7/28/2026

Usage

4 downloads · 0 views

File structure

📁 references/

📄 spam-trigger-checklist.md

📄 SKILL.md