GitHub Copilot is embedded in more developer workflows than any other AI coding tool — and skills make it dramatically more consistent. Instead of getting different quality output every time you ask for a code review, a skill gives Copilot the same procedure to follow every run.
How Copilot skills work
Skills install as SKILL.md files that Copilot reads as part of its context. They define the procedure for a specific type of task — what to check, how to respond, what format to use.
Install from the MDSkill directory with the Copilot flag:
npx mdskill add owner/repo/skill-name -a copilot
To find skills first:
npx mdskill search "test generation"
Skills that work especially well with Copilot
Copilot's strength is inline assistance — it sees the code you're actively writing and can apply skills in real time. Skills that produce incremental, inline output work best in this context.
Test generation
Test generation is one of Copilot's most-used features, and a skill makes it reliable. A good test generation skill specifies:
- Which test framework to use (Jest, Pytest, RSpec, etc.)
- Coverage targets (happy path, edge cases, error conditions)
- Naming conventions and file structure
- Whether to mock dependencies and at what level
Without a skill, Copilot improvises on all of these. With one, it follows your team's conventions every time.
Inline code review
Copilot Chat handles code review well when given clear review criteria. A skill that specifies your team's standards — performance patterns to watch, error handling requirements, logging conventions — gets you consistent reviews against your actual standards rather than general best practices.
| Review area | What a skill should specify |
|---|---|
| Performance | Patterns to flag (N+1 queries, unbounded loops, synchronous I/O) |
| Error handling | Required catch blocks, logging format, retry logic |
| Naming | Convention rules, abbreviation policy |
| Complexity | Max function length, cyclomatic complexity threshold |
Commit message generation
A commit message skill tells Copilot the exact format your team uses — Conventional Commits, a ticket prefix format, a specific length limit — so every generated message matches your git history style. Useful for teams that enforce commit lint rules.
PR description generator
Similar to commit messages but at the PR level. A skill can specify: summary format, required sections (what changed, how to test, screenshots if UI), label conventions, and how to classify breaking changes.
Skills for specific stacks
The most effective skills are stack-specific. A Next.js skill knows about App Router conventions, server vs client components, and generateMetadata. A Rails skill knows about STI pitfalls and N+1 patterns specific to ActiveRecord.
Search for stack-specific skills:
npx mdskill search "next.js"
npx mdskill search "rails"
npx mdskill search "django"
Building a custom Copilot skill
If you need something specific to your codebase — your internal component library, your API conventions, your team's definition of done — write a custom skill.
# our-pr-reviewer
## Purpose
Review pull requests against our internal engineering standards,
focusing on our React component patterns and API conventions.
## Instructions
1. Check React components use our internal UI library, not raw HTML elements
2. Verify API calls go through our centralised http client, not fetch directly
3. Flag any new dependencies not in our approved list
4. Check for missing error boundaries on async components
## Output format
- component-issue: description + file:line + recommendation
- api-issue: description + file:line + recommendation
- dependency-issue: package name + reason flagged
See how to build a skill for the full process.
What's next?
- Browse the skill directory to find Copilot-compatible skills
- Read the SKILL.md explainer to understand the format
- Compare Copilot with Claude Code and Cursor to see where skills differ