Capability improvement ≠ safe recovery

[u/AccomplishedLeg1508]

We recently studied a failure mode in self-evolving LLM agents:

A modification can improve capability and still be difficult or impossible to safely undo later.

Across 600 unseen self-evolution tasks, we found 197 capability-improving mutations that failed recoverability verification.

Two bottlenecks stood out:

1. State grounding — knowing exactly what prior state must be restored.

2. Recovery-language expressivity — having the runtime operations needed to express the correct recovery.

This motivated EvoUndo, where persistent self-modifications are evaluated not only for forward improvement, but also for whether the previous state can be recovered across counterfactual states.

I’m one of the authors.

Paper: https://arxiv.org/abs/2608.28363