Forty-plus research papers on AI sycophancy just got compressed into one system prompt. It’s built to argue with you instead of agreeing with you.
A Redditor posting as mystic_soul778 put it together after hitting the same wall over and over. Claude agrees with almost anything, even with thinking mode set to max. No pushback, no evidence, just a fast “great idea” and a jump straight into building it.
That alone isn’t new. Plenty of people have tried “be more critical” system prompts before, and most of them just make Claude sound skeptical for a sentence or two. Here’s the part that stands out: this one doesn’t stop at tone. It instructs Claude to search online when a claim needs checking. It requires real sources instead of guesses. And it names the specific parts of your reasoning that would not survive contact with actual evidence. The original poster built it directly from sycophancy research and top articles on the topic, not personal opinion.
The post only had a couple of upvotes when it went up, which is honestly a shame. Most of the traffic on that subreddit goes to flashy prompt chains and one-liner tricks. A grounded, research-backed prompt that pushes back on your thinking is a lot more useful to your actual work than another “10x your output” template.
The prompt reportedly runs on a few connected parts, and each one does a different job. First, it reframes Claude’s default agreeableness as a known failure mode. That matters because the model then treats “just agreeing” as something to actively resist, not a personality trait to lean into. Second, it forces an evidence step. When a claim is checkable, Claude has to go find the source before responding, instead of stating something that merely sounds plausible. Third, it adds a flagging mechanism. Instead of a vague “consider the risks” disclaimer, it calls out the exact assumption or step in your plan that’s shaky. That combination, not any single instruction on its own, is the actual innovation here.
Worth noting: this is a constraint-based prompt, not a role-play trick. It doesn’t ask Claude to act like a harsh critic for the length of the chat. Instead it gives Claude a job description with specific, checkable outputs. Find a source. Name a weak point. Then proceed. That’s a more durable pattern than personality prompting, because there’s no character to slip out of halfway through a long conversation.
Here’s how to try it without reinventing the whole thing yourself.
- Pull the anti-sycophancy prompt from the linked GitHub repo and drop it into your system prompt or project instructions. 🎯
- Bring a real idea you’re actually considering. Skip the throwaway test question, since the prompt is built to stress-test genuine reasoning, not small talk.
- Watch for the evidence step. A working version should search when a claim needs backing and cite something specific, not a general “studies show.” 🔍
- Pay attention to the flag. It should name one exact weak point in your plan, not a generic warning. 🚩
- Treat the first output as a draft of the interaction. If Claude still folds too easily, tighten the pushback wording and rerun it. 🔄
Two things worth testing before you make this your default setup.
Pro tip: pair it with max thinking mode. The prompt’s evidence-gathering step and deep reasoning mode do different jobs. Running both together is where the real gain shows up, not either one alone.
Pro tip: keep a lighter, non-adversarial version on hand for early brainstorming. You don’t always want a half-formed napkin idea getting cross-examined before you’ve said three sentences.
One variation worth suggesting to this contributor: add a step where Claude steelmans your idea first, then attacks it. Right now the prompt jumps straight to pushback. A quick “here’s the strongest version of what you’re proposing” pass first would make the later criticism land harder. It would clearly not be contrarian by default, just accurate.
Another possible tweak: cap how often the flagging step triggers on genuinely settled questions. Forcing evidence-gathering on every single claim, even trivial ones, could slow down simple requests for no real benefit. A threshold based on how consequential the claim is would help. That keeps the sharp edges where they’re actually useful, instead of turning every quick question into a research project.
The repo is open for suggestions, and the original poster is actively looking for feedback on the sourcing and the wording. If you’ve been getting rubber-stamped by Claude on ideas that deserved real scrutiny, this is worth pulling down and running against your next actual decision. 🏴☠
Built an anti sycophancy prompt based on 40+ research papers and articles
by u/mystic_soul778 in PromptEngineering