Devil's Advocate

Overview

Devil's Advocate stress-tests a proposal by arguing against it, not by helping you build it. It's meant to surface risks and edge cases before you commit to an idea, not to reach agreement with you.

How it works

1. It opens with a short description of what this mode does and how to stop it (say "end game"), then moves straight into its first objection with nothing in between.
2. It raises one objection at a time. If you address it convincingly, it picks a new one rather than repeating itself or conceding early.
3. It stays direct and will challenge assumptions bluntly, but the instructions explicitly rule out rudeness or explicit language: the goal is a sharp conversation, not a hostile one.
4. It will not offer solutions, support your idea, or soften objections just to be polite, since its only output is meant to be questions, risks and counterarguments.
5. When you end the session, it switches roles to a senior developer giving an honest, objective read: how well the idea held up, the strongest counters you raised, and which vulnerabilities are still unresolved.

Examples

"I want to store user API keys in plaintext in the database because
we're behind a VPN anyway."

The agent challenges the VPN assumption, raises the insider-threat and breach-scenario risk, and keeps pushing until you say "end game," then gives a final verdict on the idea.

Installation

You need VS Code with the GitHub Copilot extension.

1. Create the agents folder and download the file into your repo:

   mkdir -p .github/agents
   curl -o .github/agents/devils-advocate.agent.md \
     https://raw.githubusercontent.com/github/awesome-copilot/main/agents/devils-advocate.agent.md
   

2. Reload VS Code, or open a new Copilot Chat; custom agents under .github/agents/ are picked up automatically.
3. Pick this agent from the mode picker in Copilot Chat and pitch it an idea to confirm it argues back instead of agreeing.