From Agent Traces to Steering Signals—Without Fine-Tuning
TL;DR for operators A capable AI agent encounters a tool error, adjusts its approach, and eventually completes a workflow. A smaller agent attempting the same task may fail. Improving the smaller agent does not necessarily require training it to imitate the entire successful execution. REVEAL1 converts textual histories of successful and failed frontier-agent runs into activation controls constructed inside a frozen target model. On Terminal-Bench 2.1, it raises Qwen3.6-27B accuracy from 33.71% to 39.33%, compared with 35.96% after trajectory supervised fine-tuning (SFT). Its average online input-token consumption is also 35.60% lower than SFT. ...