A safety safeguard that has to pick the right rule first, because guessing wrong makes the safety verdict wrong
AspireAI community · arXiv (cs.AI)
Most policy-aware safeguards assume the applicable policy is already known, so a wrong choice produces a wrong safety judgment that no downstream check catches. RePolicy learns policy selection and safety assessment jointly, given a trajectory and a library of candidate policies, and is trained on PolicyTraj-20K, more than 20,000 agent trajectories annotated with applicable policies, safety labels and explanations, using supervised demonstrations then reinforcement learning, with policy order, identifiers and distractors randomized to block shortcut learning. Across six agent-safety benchmarks and 19 baselines, the 4B variant leads on overall safety detection and improves policy-selection accuracy.
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Two sparse-autoencoder analyses have resisted scaling: matching semantically similar features across layers, and compressing large feature circuits into interpretable supernodes. This paper argues both are the same underlying problem, estimating semantic distances between SAE features that sit on different activation manifolds. Its representation treats each feature not as a single decoder vector but as an activation-weighted distribution over the hidden states expressing it, projects those distributions into a shared reference space, and compares them with Wasserstein distance. The representation is proved invariant to activation rescaling and stable under perturbation, and recovers true matches under finite-sample margin conditions. Empirically it outperformed decoder-vector and LLM-based baselines and captured subtle functional distinctions between related features, and it compressed large feature circuits into interpretable supernodes automatically. The limitation is that this is interpretability tooling: the paper demonstrates better feature matching and circuit compression, not that downstream interpretability claims become more accurate.