Custom Skill Authoring and Test Loop
Turn a rough workflow into a self-contained SKILL.md, realistic trigger tests, and evidence-based revisions.
Before & after
Same prompt, same agent — the only difference is the skill.
That's a useful skill to build. I could help you create a starting point by outlining what you'd want the skill to do—basically, it would take your brand voice and generate subject lines that match your tone. You'd probably want to define what your brand voice looks like, maybe give some examples, and specify what kinds of subject lines matter most. From there, we could draft some instructions and test them out with different scenarios. You might want to include parameters like length constraints or the emotion you're trying to evoke. We'd probably need to iterate on the results to make sure they feel right. Would you like to start by describing your brand voice in detail, or would you rather work from existing subject lines?
SKILL CREATOR: BUILD EMAIL SUBJECT LINE SKILL INTERVIEW PHASE → What is your brand voice? (tone descriptors: e.g., "helpful but direct", "witty and irreverent") → What do you NEVER want in a subject line? (banned words, banned approaches) → What's the ideal character count? → Who is the audience for these emails? → What job should each subject line do? (create urgency / curiosity / trust / action) DRAFT SKILL.MD → Instructions locked to your voice specs → Guardrails that block banned patterns → Examples from your best past subject lines → Output format: plain text, max 60 chars TEST PHASE (3 test prompts run) → Prompt 1: New product launch email → Prompt 2: Customer win-back offer → Prompt 3: Educational/thought leadership EVALUATION → You score each result (1-5) → Score feeds revision loop → Changes locked when you confirm DELIVERABLE → Packaged skill folder → Ready to install into Claude Code → Your SKILL.md and test prompts included
About this skill
“I want a skill that does this” often turns into a long prompt that still needs constant correction. This workflow turns your idea into a usable SKILL.md by extracting the decisions, edge cases, and acceptance criteria that generic instructions miss, then building realistic tests for revision.
What it does
- Interviews you about the task, accepted inputs, failure cases, and situations where the skill should stay inactive.
- Converts preferences into operational rules, measurable limits, and worked examples.
- Drafts a complete, self-contained SKILL.md with precise activation language.
- Creates five realistic test prompts covering normal work, difficult inputs, missing details, and neighboring requests.
- Separates proposed tests, manual walkthroughs, and actual execution results so readiness claims stay accurate.
- Revises the rule responsible for a failure and reruns affected cases when an execution environment is available.
What you get
A complete SKILL.md, a compact test suite with expected behavior and scoring criteria, and a revision record showing what changed and what remains untested. If isolated execution is unavailable, you still receive the draft and ready-to-run tests with that limitation stated plainly.
Best for
Designers, product managers, operators, and developers turning a repeated Claude workflow into a reusable skill, especially when an earlier draft activates too broadly or produces inconsistent results.
SKILL.md preview
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name: custom-skill-authoring-and-test-loop
description: >-
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