Lesson 1.2: Create Your First Skill

🎯 What You'll Learn: How to build a working skill file that automates your Quick Win
⏱️ Time Required: 50 minutes
📦 What You'll Build: A complete SKILL.md file that runs YOUR automation

Riley's Journey Continues

In Lesson 1.1, Riley identified her Quick Win: the weekly margin report that consumed 4 hours every Monday.

Now she's ready to build.

💬 "I'll be honest - when I heard 'create a skill file,' I thought we'd be coding. Turns out, it's more like writing really clear instructions. If you can explain your process to a new team member, you can write a skill."
— Riley Harper

Where Riley is now:

By the end of this lesson:

What We're Building in This Lesson

A skill is just YOUR process, written down clearly. If you can explain your task to a colleague, you can write a skill.

In this lesson:

Key Concept: What Is a Skill?

Think of a skill like a company SOP (Standard Operating Procedure).

A skill has two parts:

┌─────────────────────────────────────┐
│  PART 1: FRONTMATTER (YAML)         │
│  ─────────────────────────────      │
│  • name                             │
│  • description                      │
│  • author                           │
│  • version                          │
│  (The cover page of your SOP)       │
├─────────────────────────────────────┤
│  PART 2: INSTRUCTIONS (Markdown)    │
│  ─────────────────────────────      │
│  • When to use this                 │
│  • Step-by-step process             │
│  • Examples of output               │
│  (The actual procedures)            │
└─────────────────────────────────────┘

Exercise: Build Your Skill

⏱️ Total Time: 50 minutes

What You'll Build

🔧 A complete SKILL.md file for your Quick Win that Claude can load and execute.

Before You Start

You'll need:

Riley's starting point:

Quick Win: Weekly Margin Report
Current process:
1. Pull data from Prime Broker portal
2. Copy into Excel template
3. Calculate variance from last week
4. Format and email to portfolio managers

Step 1: Create Your Skill Folder

⏱️ Time: 5 minutes

What you're doing:

Setting up the folder structure where Claude looks for skills.

Command to run:

mkdir -p .claude/skills/YOUR-SKILL-NAME

Naming rules:

Examples:

Riley's command:

mkdir -p .claude/skills/weekly-margin-report

💬 "I was nervous about the command line, but it's literally just one command. Copy, paste, replace the name with yours, done."

✅ Success Check:

Step 2: Create the SKILL.md File

⏱️ Time: 5 minutes

What you're doing:

Creating the file that will contain your skill instructions.

Command:

touch .claude/skills/YOUR-SKILL-NAME/SKILL.md

Or create it directly in your editor:

⚠️ Important: The filename must be exactly SKILL.md (capital SKILL, lowercase .md)

Riley's file location:

.claude/
└── skills/
    └── weekly-margin-report/
        └── SKILL.md  ← This file

✅ Success Check:

Step 3: Write the Frontmatter

⏱️ Time: 5 minutes

What you're doing:

Adding the metadata header that tells Claude about your skill.

Template to copy:

---
name: your-skill-name
description: One sentence describing what this does and when to use it. Start with action verb.
author: Your Name
version: 1.0
---

Riley's frontmatter:

---
name: weekly-margin-report
description: Generates weekly margin report from Prime Broker data for portfolio manager distribution. Use every Monday morning.
author: Riley Harper
version: 1.0
---

Tips for the description:

💡 Pro Tip: Include WHEN to use this skill in the description. Claude uses this to know when to activate it automatically.

✅ Success Check:

Step 4: Write the Overview & Triggers

⏱️ Time: 5 minutes

What you're doing:

Telling Claude what this skill does and when to use it.

Template:

# [Your Skill Display Name]

## Overview
[2-3 sentences: What this skill does and why it's valuable]

## When to Use This Skill
Activate this skill when:
- [Trigger phrase 1]
- [Trigger phrase 2]
- [Trigger phrase 3]

Riley's version:

# Weekly Margin Report Generator

## Overview
Automatically compiles margin data and formats it into the standard weekly report for portfolio managers. Reduces report creation from 4 hours to 18 minutes while ensuring consistent formatting.

## When to Use This Skill
Activate this skill when:
- User asks to create margin report or weekly report
- User mentions "Monday report" or "PM report"
- User needs Prime Broker data compiled
- It's Monday and user asks about reports

💬 "The trigger phrases are like teaching Claude the keywords that should activate this skill. I added 'Monday report' because that's what I actually call it."

✅ Success Check:

Step 5: Document Your Process

⏱️ Time: 15 minutes

What you're doing:

This is the heart of your skill - writing out YOUR process step by step.

Template:

## Process

### Step 1: [First Action]
[What Claude should do]
[What to ask the user, if anything]

### Step 2: [Second Action]
[What Claude should do]
[What to ask the user, if anything]

### Step 3: [Continue...]
[...]

### Final Step: [Output/Delivery]
[How to format and present the result]

Riley's Process:

## Process

### Step 1: Gather Current Week Data
Ask the user to provide or paste:
- Current margin balance
- Exposure by asset class
- Top 5 positions by size
- Any notable changes from last week

### Step 2: Collect Prior Week Comparison
Ask the user for last week's key figures:
- Prior margin balance
- Prior exposure total
- Note: If user has these saved, they can skip this step

### Step 3: Calculate Variance
For each data point:
- Calculate week-over-week change
- Calculate percentage change
- Flag any changes greater than 10%

### Step 4: Format the Report
Structure the output as:
- Header with date range
- Executive summary (3 bullet points)
- Margin summary table
- Exposure breakdown table
- Notable changes section
- Recommended actions (if any flags)

### Step 5: Generate Email Draft
Create email version with:
- Subject line: "Weekly Margin Report - [Date Range]"
- Brief intro paragraph
- Report as attachment or inline
- Offer to adjust tone/detail level

Writing Tips:

💬 "I wrote this like I was training a new analyst. Every step I'd normally explain, I wrote down. The more specific, the better the output."

✅ Success Check:

Step 6: Add an Example

⏱️ Time: 10 minutes

What you're doing:

Showing Claude exactly what the output should look like.

Why this matters:

Claude performs MUCH better when it can see the target. An example is worth 1000 words of instructions.

Template:

## Example Output

[Paste a real or realistic example of what the final deliverable looks like]

Riley's Example:

## Example Output

**WEEKLY MARGIN REPORT**
**Week of:** January 13-17, 2025
**Prepared by:** Riley Harper

---

**EXECUTIVE SUMMARY**
- Total margin increased 3.2% week-over-week to £45.2M
- Equity exposure up £2.1M due to new tech positions
- No concentration warnings; all within limits

---

**MARGIN SUMMARY**

| Metric | Current | Prior | Change |
|--------|---------|-------|--------|
| Total Margin | £45.2M | £43.8M | +3.2% |
| Available | £12.1M | £11.8M | +2.5% |
| Utilization | 73.2% | 73.1% | +0.1% |

---

**EXPOSURE BY ASSET CLASS**

| Asset Class | Exposure | % of Total | WoW Change |
|-------------|----------|------------|------------|
| Equities | £28.4M | 62.8% | +5.2% |
| Fixed Income | £12.1M | 26.8% | -1.1% |
| Alternatives | £4.7M | 10.4% | +0.8% |

---

**NOTABLE CHANGES**
- ⚠️ Tech sector exposure increased 12% (above 10% threshold)
- New position: NVDA (£1.2M)
- Closed position: META (£0.8M)

---

**RECOMMENDED ACTIONS**
- Review tech concentration with PM before EOD
- No other actions required

💬 "This example is basically my real report with the numbers changed. When Claude sees this format, it produces something almost identical. Magic."

✅ Success Check:

Step 7: Test Your Skill

⏱️ Time: 10 minutes

What you're doing:

Verifying your skill loads and works correctly.

Instructions:

   /clear
   

   /skills
   

Your skill should appear in the list.

   Create my weekly margin report
   

Riley's Test:

💬 "First test, it worked but the table formatting was slightly off. I added more detail to my example, tested again, and it was perfect. Iteration is normal."

If it doesn't work:

✅ Success Check:

Overall Success Criteria

By the end of this lesson, you should have:

Quick Test:

If all four pass, you've built your first skill!

Troubleshooting

# Wrong
description: Generates "reports" & summaries

# Right
description: "Generates reports & summaries"

You Did It!

You just built your first automation skill!

What Riley accomplished:

💬 "Four hours of Monday morning dread, now 18 minutes of answering prompts. Same quality output - actually better, because the format is always consistent now. I almost didn't believe it worked the first time."

The transformation:

Your skill is now:

💡 The pattern: Everyone spends the most time on the process steps and the example output. That's exactly where you should invest, those two sections determine 90% of the quality.