Skill Usage and Design

Pingfan Hu & Dr. John Helveston
George Washington University

Agentic Workflows with Claude Code

Today

Everything about a skill splits into three things you do with it.

Using Skills

Summon a workflow by name with /

Installing Skills

Borrow from the open-source market

Authoring Skills

Encapsulate your own workflow, once

Without vs with a skill

Example: Deploying a Mac app

Without a skill

1Update the version number

2Build the release

3Sign & notarize with Apple

4Wire up auto-updating

5Publish the release on GitHub

With a skill

Use the /mac-app skill
to deploy the Mac app.

Without vs with a skill

Example: Creating an image

Without a skill

1Pick the right AI image model

2Set up the API access

3Write a detailed style prompt

4Run the generation script

5Clean up & export the PNG

With a skill

Use the /create-image skill
to generate an image of a sunset.

What is a skill?

A slash command that wraps a reusable, multi-step process.

File Structure

my-skill/

Invoke it

Use /my-skill
to do something...

Skill usage example: the Waza plugin

/think

Plan before coding

/ui

Craft the frontend

/hunt

Find root causes

/check

Review & ship

/write

Polish your prose

/read

Digest URLs & PDFs

/learn

Research a domain

/health

Audit your setup

Let’s use /read to summarize

Blog post of Prof. Helveston about the effectiveness of Quarto

Prompt

Use the /read skill to read through the url of this blog post and summarize the takeaways.

Takeaways

One source, any format

Up to 7× fewer tokens

Always current at render time

Plain text, clean Git diffs

 

— practice 01 —

Install Waza, use a skill, inspect its pipeline.

Install

Add the Waza plugin, following its README.

Use

Run one skill on a real task and judge the quality of the result.

Inspect

Ask your agent about the skill's pipeline to understand how it boosts efficiency.

Let’s create a skill!

1

Create a GitHub repo for your skills

2

Open the path in Positron

3

Launch Claude Code in Positron

Let’s create a skill!

---
name: my-skill
description: What it does and when to use it.
---

# My Skill

State the goal in one line.

## Steps

1. First step here.
2. Next step here.

## Notes

- A rule or example to follow.

my-skill/SKILL.md

---

name: my-skill

description: What it does and when to use it.

---

# My Skill

State the goal in one line.

## Steps

1. First step here.

2. Next step here.

## Notes

- A rule or example to follow.

name

The skill's id and slash command. Lowercase, kebab-case.

description

One line. How the AI decides when to reach for the skill.

body

The prompt loaded on invocation: steps, rules, examples to follow.

Start from this template and build your skill with the help of AI.

Create symlinks

Skills Repo

my-skills/

multiple skills + a shell command

Stay in sync

Every time you author a new skill, just ask Claude Code to run the command again.

Just ask Claude Code

Run sync-skills.sh to update my skill symlinks in the skills folder.

More sophisticated skills

A full pipeline

App Deployment

Multiple AI agents

Image Generation

Subsections for a same topic

/surveydown-skill

Skill for a full pipeline

A /mac-app skill for the full deployment pipeline

File structure

mac-app/

Skill pipeline

1Update the version number

2Build the release

3Sign & notarize with Apple

4Wire up auto-updating

5Publish the release on GitHub

Skill for multi-agents

A /create-image skill with APIs to 3 image models

File structure

create-image/

Output

Skill for a same topic

A /surveydown-skill that wraps up multiple usages of surveydown.

File structure

surveydown-skill/

├─ SKILL.md

├─ author/

│ ├─ create-survey/

│ └─ connect-database/

├─ deploy/

│ ├─ hugging-face/

│ ├─ google-cloud/

│ └─ posit-cloud/

└─ demo/

└─ record-video/

One topic

surveydown

Author a survey

Deploy to any host

Demo with a recording

 

— practice 02 —

Build and test your own skill.

Create repo

Stores your skills and the symlink shell command.

Author a skill

Make one that matches your own needs.

Load and test

Load it in your agent session and try it out.

 

Randomness

Nature of LLMs

VS

Determinism

What we desire

Randomness naturally exists in LLMs

/create-image "a white cat, vintage Japanese travel poster"

Consistent theme but varied details.

Workarounds for Determinism

Cooking Oil

Light Soy Sauce

Tomato Paste

Template

One base bottle for every cooking liquid.

Script

Image-to-image scripts based on the template.

Post-processing

Label stamped afterwards: fixed font, size, and color.

Skills, in summary

Start minimal

One SKILL.md is enough to begin.

Pin the deterministic parts

Templates and scripts keep what must hold still.

Bundle workflows

One skill can hold many abilities under one theme.

Nest other agents

Delegate the task your agent is weak at.

My takeaway

"

A skill is not for the agent's benefit. The agent does not distinguish a skill from a temporary prompt: it just reads files and context. We make skills for the humans, to encapsulate a workflow worth keeping.