Five commercial assistants were audited on when they search, and one of them searched on just 20% of questions that needed it
AspireAI community · arXiv
Agentic assistants have to decide repeatedly whether to answer from memory or call a tool such as web search, and that decision is rarely audited in deployed products. This study builds a 400-question benchmark mixing widely known inside-knowledge questions, which should be answered directly, with outside-knowledge questions about news published after the models' training cut-offs, which should trigger a search or, tool-less, an abstention. Two action-level scores reward searching on the outside-knowledge items and restraint on the inside-knowledge ones. GPT-5 mini and Grok 4 Fast searched on more than 90% of outside-knowledge questions but only 1% of inside-knowledge ones, while Mistral Small searched on just 20% of outside-knowledge questions and often abstained instead of using its tool; one product's search indicator proved unusable. Temporal cues matter too: on uncued outside-knowledge questions the selective models' search score falls from about 0.72 to 0.57-0.58, and the authors note these scores measure product behavior rather than metacognition in a strict sense.
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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.