Copilot Studio Skill Builder

A personal, community-shared skill that helps you design, challenge, generate, and repair Microsoft Copilot Studio system prompts and skills — from a real use case and a proposed architecture.

Skill version: V1.0 — created on 6 August 2026. Copilot Studio, its harnesses, its skills, and its billing evolve very quickly. Always check the creation date of this skill and re-verify the official Microsoft sources before treating any point as current.

⬇️ Download the skill

Download latest

Then, in Copilot Studio, go to Build → Skills → Upload a skill and import the ZIP.

Why this project

The Microsoft Power CAT team publishes official, community catalogs of reusable skills for AI agents (Cowork, Copilot Studio, and Scout) at https://microsoft.github.io/cat-agent-skills/. Those catalogs are the reference starting point for ready-to-use skills.

This is not a replacement for them — it is a complement. copilot-studio-prompt-skill-builder is the personal skill I actually use, in addition to the official resources, when I build agents. It packages three things that generic documentation rarely captures together:

  • my design methodology for turning a use case into the simplest deliverable that works;
  • the frequent mistakes AIs make when building Copilot Studio agents (packaging, JSON contracts, file transport, over-architecting, inventing connector actions…);
  • efficient, field-tested guidelines to avoid those mistakes.

It is shared openly so the community can use it, adapt it, and improve on it.

What it does

Given a use case and a macro architecture, the skill helps you:

  • DISCUSS — reformulate the need, highlight strong points, challenge only the high-impact decisions, and recommend a deliverable level (no files generated by default).
  • BUILD — produce the minimal deliverable: a system prompt, a system prompt + a Markdown skill, a system prompt + a complex ZIP skill, or multiple skills.
  • REVIEW / REPAIR — inspect the exact deployed artifact and apply the smallest safe correction, instead of rebuilding everything.

Core principle: a complex use case does not automatically require a complex skill. Complexity must answer a demonstrated need.

What's in this repository

Copilot-Studio-Skill-Builder/
├── copilot-studio-prompt-skill-builder-v1.0.zip   # ready-to-upload skill package
├── skill/                                          # the same skill, unpacked and browsable
│   ├── SKILL.md                                    # central method (modes, decisions, flow)
│   ├── host-system-prompt.md                       # recommended host-agent system prompt
│   ├── references/                                 # design method, lessons learned, rules, contracts, research protocol
│   ├── templates/                                  # system-prompt and skill templates
│   ├── scripts/validate_skill_package.py           # package structure validator
│   └── examples/                                   # request examples
└── docs/
    └── guide.md                                    # full user guide (13 chapters)

Quick start

In Copilot Studio

The new experience based on the GitHub Copilot harness supports skills imported as a Markdown file or as a ZIP with SKILL.md at the root.

  1. Open your host agent, go to Build, then Skills.
  2. Choose Upload a skill and import copilot-studio-prompt-skill-builder-v1.0.zip.
  3. Use skill/host-system-prompt.md as the base of your host-agent instructions.
  4. Add the tools you need for Microsoft research and file generation.
  5. Test one DISCUSS, one BUILD, and one REVIEW / REPAIR scenario.

Availability, harness, consumption, and limits change over time — re-verify them on Microsoft Learn at deployment time. Building, testing, and evaluating agents on the GitHub Copilot harness can consume Copilot Credits.

With another AI assistant

Attach the ZIP (or the skill/ folder) to your conversation and explicitly ask the assistant to start with SKILL.md. The ability to actually produce a ZIP or a document depends on the tools available in that assistant.

Validate a skill package

python skill/scripts/validate_skill_package.py copilot-studio-prompt-skill-builder-v1.0.zip
# or validate an unpacked folder:
python skill/scripts/validate_skill_package.py skill/

The validator checks for SKILL.md at the ZIP root, a valid name/description front matter, UTF-8 encoding, forbidden temporary files, and wrapper-folder mistakes.

Documentation

The complete user guide is in docs/guide.md — 13 chapters covering the method, the working modes, deliverable selection, architecture challenges, output and file contracts, review/repair, anti-patterns, examples, and checklists.

Contributing and feedback

This is a living skill: it should grow from real, reproducible cases. Issues and suggestions are welcome. Every new rule should map to an actual incident or a recurring need, so the skill stays focused instead of becoming bloated.

Author

Created and maintained by Romain Gerard — Microsoft MVP, Copilot Studio.

License

Released under the MIT License. You are free to use, modify, and share it, provided the copyright notice is preserved.