A learned memory-skill bank beats fixed insert/update/delete baselines by 5-7 points, on 6x fewer LLM calls
Notes on MemSkill: Learning and Evolving Memory Skills for Self-Evolving Agents (arXiv:2602.02474) — Haozhen Zhang, Quanyu Long, Jianzhu Bao, Tao Feng, Weizhi Zhang, Haodong Yue, Wenya Wang · February 2026
Note published · written by SkillFed’s research pipeline from the paper above · how these notes are made
AI-assisted notes · reviewed by SkillFed Skill evolutionMemSkill treats the four hard-coded memory operations — insert, update, delete, skip — that most LLM agent memory systems run on as a starting point, not the final word. It organizes them into a shared skill bank, a set of structured, reusable routines for extracting, consolidating, and pruning information from interaction history. Three learned components run that bank: a controller, trained with reinforcement learning (PPO) and Gumbel-Top-K sampling, picks a small set of relevant skills for each turn without replacement; an executor applies whichever skills got picked to write memory in a single pass over a span of history, rather than turn by turn; and a designer periodically reviews the hard cases — where selected skills produced wrong or incomplete memories — clusters similar failures, and proposes refinements or entirely new skills. That closes the loop: the selection policy and the skill set itself both keep improving over time.
MemSkill beats the strongest baselines tested — MemoryOS, Mem0, A-MEM, and Chain-of-Note — across LoCoMo and LongMemEval (conversational memory QA), HotpotQA (used to test distribution shift across document-context lengths), and ALFWorld (embodied, multi-step tasks). On LoCoMo with LLaMA 3.3 70B it scores 44.21 F1 / 53.82 LLM-judge against 41.39 / 48.64 for the best baseline; on ALFWorld it reaches 77.14% / 83.58% success on seen/unseen tasks against 74.29% / 81.34%. Swap in Qwen3-Next 80B with no retraining and the gains hold: LoCoMo LLM-judge 54.14 vs. 47.37, ALFWorld average success 81.29% vs. 74.02%. An ablation shows why: on the harder Qwen transfer setting, dropping the designer alone drags LoCoMo LLM-judge from 54.14 down to 36.15 — a steeper fall than dropping the controller, so both learned pieces are earning their keep. It's cheaper, too: on LoCoMo, MemSkill runs roughly 249K input tokens and 215 LLM calls, against about 1M tokens / 1,288 calls for MemoryOS and 2.85M tokens / 1,548 calls for A-MEM.
Key numbers
| LoCoMo score vs. best baseline (LLaMA 3.3 70B) | 44.21 F1 / 53.82 L-J vs. 41.39 / 48.64 |
| ALFWorld success, seen / unseen (LLaMA 3.3 70B) | 77.14% / 83.58% vs. 74.29% / 81.34% |
| LoCoMo L-J w/o designer, Qwen transfer (ablation) | 54.14 → 36.15 |
| LoCoMo cost: input tokens / LLM calls | 249K / 215 vs. up to 2.85M / 1,548 for baselines |
| LongMemEval L-J, transfer setting (no training) | 60.89 vs. 56.44 best baseline |
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References
- Zhang, H., Long, Q., Bao, J., Feng, T., Zhang, W., Yue, H., & Wang, W. (2026). MemSkill: Learning and Evolving Memory Skills for Self-Evolving Agents. arXiv:2602.02474.
- Mem0 — production-oriented long-term memory system for LLM agents, used as a baseline in this paper.
- MemoryOS — OS-inspired memory management framework for AI agents, used as a baseline in this paper.
- A-MEM — agentic memory framework for LLM agents, used as a baseline in this paper.
- LoCoMo — long-term conversational memory benchmark used for evaluation in this paper.