Diagnosing Agent Memory

This paper introduces a diagnostic framework that separates retrieval failures from utilization failures in LLM agent memory systems. Through a 3x3 factorial study crossing three write strategies with three retrieval methods, the authors find that retrieval is the dominant bottleneck, accounting for 11-46% of errors, while utilization failures remain stable at 4-8% regardless of configuration. Hybrid reranking cuts retrieval failures roughly in half, delivering larger gains than any write strategy optimization.