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Same AI agent, different prompts: 0% vs. 62% security pass rate
I've been testing production AI agents for vulnerabilities.
Interesting finding: System prompt design matters more than the model itself.
Same agent. Same task. Same attack vectors. Only difference: how the system prompt was structured.
Results: → Prompt A: 0% pass rate (failed every test) → Prompt B: 62.5% pass rate
No model change. No fine-tuning. Just prompt engineering.
Anyone else seeing this pattern? What's your approach to hardening AI agents?