Re-derivability Decides What a Staged Agent Pipeline Recovers After an Upstream Fault
Re-derivability, not extra stages, decides how staged LLM agents recover after an upstream fault.
The study argues that re-derivability determines how much accuracy a staged language-model agent pipeline recovers after an upstream fault. One deterministic fault is injected into the first stage, and the original problem is re-exposed to zero through three downstream stages on 120 gsm_hard items at temperature zero. Accuracy under fault rises on all four open-weight backbones, from +0.233 to +0.392. On Qwen3-14B the first re-grounded stage buys +0.394 matched retention for 59.8 extra tokens, while later stages add nothing, and with no fault the pipeline loses to one direct call on three backbones.
44