Skillpack skill-creator

Create new skills, modify and improve existing skills, and measure skill performance. Use when users want to create a skill from scratch, edit, or optimize an existing skill, run evals to test a skill, benchmark skill performance with variance analysis, or optimize a skill's description for better triggering accuracy.

install
source · Clone the upstream repo
git clone https://github.com/CreminiAI/skillpack
Claude Code · Install into ~/.claude/skills/
T=$(mktemp -d) && git clone --depth=1 https://github.com/CreminiAI/skillpack "$T" && mkdir -p ~/.claude/skills && cp -r "$T/templates/builtin-skills/skill-creator" ~/.claude/skills/creminiai-skillpack-skill-creator && rm -rf "$T"
manifest: templates/builtin-skills/skill-creator/SKILL.md
source content

Skill Creator

Create new skills and iteratively improve them inside this SkillPack. Determine where the user is in the create → draft → test → improve cycle and help them move forward.

Pack-specific rules

All skills live under

{{SKILLS_PATH}}/<skill-name>/SKILL.md
and config is at
{{PACK_CONFIG_PATH}}
. These paths override any generic advice. Never create skills in the current workspace directory — always use
{{SKILLS_PATH}}
.

Creating a skill

Capture intent

Extract answers from the current conversation first, then fill gaps with targeted questions. Confirm before writing the first draft:

  1. What should this skill enable the model to do?
  2. When should this skill trigger?
  3. What output should it produce?
  4. Does the user want a lightweight draft, or a tested and iterated skill?

Clarify edge cases, input/output formats, success criteria, and dependencies as needed before writing test prompts.

Write the skill

Create the skill at

{{SKILLS_PATH}}/<skill-name>/SKILL.md
. Example template:

---
name: example-skill
description: "Analyze competitor pricing pages and generate a comparison matrix. Use when the user wants to benchmark pricing tiers, feature gaps, or positioning against specific competitors."
---

# Example Skill

## Workflow

1. Collect the target URLs from the user.
2. Extract pricing tiers, features, and limits from each page.
3. Generate a comparison matrix as a markdown table.

## Output

Return a markdown table with one column per competitor and one row per feature.

The

description
is the primary triggering mechanism — make it concrete with both what the skill does and when to use it. Keep the body focused on workflow, decisions, and output expectations. Place deterministic helpers under
scripts/
and long reference material under
references/
.

Preserve the existing skill name when improving unless the user explicitly requests a rename.

Sync skillpack.json

After creating or updating a skill, sync

{{PACK_CONFIG_PATH}}
. Read the final
SKILL.md
, parse the YAML frontmatter, and upsert into the
skills
array:

{
  "name": "<frontmatter.name>",
  "description": "<frontmatter.description>",
  "source": "./skills/<frontmatter.name>"
}

All three fields must come from frontmatter — do not guess from memory. Update existing entries instead of creating duplicates.

Writing guide

Prefer imperative instructions. Structure skills as: purpose, trigger guidance, required inputs, step-by-step workflow, output format, edge cases. For multi-domain skills, organize references by variant and tell the model how to choose.

Test and iterate

After drafting the skill, propose 2–3 realistic test prompts phrased as a real user would.

If the user wants evaluation, run the prompts, compare outputs against expectations, note failures, and revise. Otherwise, do at least a lightweight sanity check before calling the skill complete.

Improving an existing skill

When updating an existing skill:

  • preserve its canonical
    name
    unless the user explicitly asks to rename it
  • keep the directory aligned with the canonical skill name
  • update
    SKILL.md
    first
  • then re-read the final frontmatter and sync
    {{PACK_CONFIG_PATH}}

Focus on general improvements rather than overfitting to one example. Keep the prompt lean and remove instructions that are not earning their place.

Completion checklist

Before you say the work is done, verify all of the following:

  • the skill exists under
    {{SKILLS_PATH}}/<skill-name>/SKILL.md
  • SKILL.md
    has
    name
    and
    description
    frontmatter
  • {{PACK_CONFIG_PATH}}
    has a matching entry in
    skills
  • the
    source
    field is
    ./skills/<skill-name>
  • you have either tested the skill or explicitly told the user what remains untested