Your LLM Doesn’t Need Better Prompts — It Needs an Agent Harness

Reddit r/AI_Agents News

Summary

An article discusses the need for Agent Harness Engineering—structured systems with tool validation, context management, guardrails, telemetry, and verification loops—to make LLM agents reliable in production, arguing that better prompts alone are insufficient.

Built an AI agent. Thought the hard part was done. Demo? 🔥 Production? 💀 The agent confidently claimed it checked webpages it never opened, skipped verification, and hallucinated tool outputs. That’s when I realized: **LLMs don’t just need better prompts — they need better systems.** I’ve been exploring **Agent Harness Engineering** — adding structure around agents through: ✅ Tool validation 🧠 Context & state management 🛡️ Guardrails 📊 Telemetry & traces 🔁 Verification loops ⚖️ LLM-as-a-Judge auditing Simple idea: **Prompts tell the model what to do.** **Harnesses make sure it actually did it.**
Original Article

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