How to build an AI agent harness that actually improves performance
Drawing on 57 research papers and practical experience, this approach optimizes the external wrapper (harness) around AI models to significantly boost agent performance, reduce token consumption, and cut latency. The core principles involve streamlining instructions, reducing redundant tools, enforcing rules with scripts, and regularly cleaning up documentation.
Added 2026-10-31 · originally published 2026-10-30
Steps
- 1Mine patterns from previous sessions, turning past failures into rules and adding missing guidance or guardrails every time you correct the agent.
- 2Delete rules that cannot prove their usefulness, keeping instruction files short (such as keeping the main AGENTS.md around 100 lines as a directory pointing to other rules).
- 3Streamline by using fewer, sharper tools, removing unnecessary ones to improve success rates and lower latency.
- 4Back up and enforce rules with executable scripts (such as git hooks, linter rules, static code analysis, or custom scripts) rather than relying solely on text prompts.
- 5Regularly prune and maintain the harness by clearing out stale rules and outdated documentation.
Ideas for Chinese platforms
This method can be migrated to automated operations on Xiaohongshu or official WeChat accounts: streamline SOP instruction documents (keeping them under 100 lines), enforce rules with fixed scripts or workflow tools, and regularly clean up outdated talking points to significantly reduce noise in AI-generated content and improve stability.
Please help me review and optimize the instructions and tool configurations I provide to my AI agent. Here is the current instruction file content: [Paste AGENTS.md or instruction content here] Here are the errors I've encountered or scenarios where I needed to correct the agent: [Describe past session failures or correction logs here] Please help me: 1. Turn these failures into concrete candidate rules. 2. Streamline the instructions so it acts like a directory pointing to other rules (keeping it around 100 lines). 3. Help me identify and remove redundant rules and tools that provide no substantive help.
Related use cases
Summarized by AI from the original source - refer to the original post for details. Copyright belongs to the original author.