When Harnesses Lose the Signal: causal evaluation of recovery in LLM agents and the Causal Intervention Router (CIR)
The paper frames recovery in LLM agents as a causal decision problem, comparing outcomes from the same execution state with and without recovery to separate rescue from harm and to track how recovery value changes over time. It introduces the Causal Intervention Router (CIR), a lightweight policy that decides whether to intervene using pre-recovery information; on long-horizon ALFWorld tasks with Qwen3-14B CIR raised success from 70.33% to 73.33% and left trajectories with correct observations untouched, with controls indicating benefits are not solely due to the new observation returned by the environment.