arXiv AI

Invalidation Contracts for Cross-Episode Agent Memory

The paper proposes invalidation contracts to manage cached recovery suggestions in LLM agents, attaching version stamps and cacheability hints to each suggestion so stale entries can be evicted without trial and error. The protocol separates realized savings into validity (protocol‑dependent) and compliance (planner‑dependent), showing that row‑level invalidation can significantly improve first‑try compliance and recover a substantial portion of token costs across multiple models, while table‑level invalidation can be detrimental. The study evaluates the approach across seven models, three serving paths, two domains, and about 9,400 episodes, demonstrating deterministic validity and high eviction precision.

arXiv AI
Sep 25

Where Does Exactly-Once Live? Model, Harness, and Tool-Contract Effects on Duplicate Side Effects in LLM Agents

The paper investigates where exactly‑once semantics should be enforced for tool‑using agents—within the model, the agent harness, or the tool contract—by evaluating 25,930 episodes across nine models, three harnesses, two contract variants, and fifteen recovery conditions. Using the LIMBO sandbox, the study shows that when an immediate read‑back is available, frontier models rarely duplicate lost acknowledgements, whereas weaker models do; when read‑back is unavailable, the contract’s idempotency keys explain most duplicate behavior. The authors prove that verification‑only policies cannot guarantee exactly‑once under late commits without bounded in‑flight time, and that waiting only helps when delays are short and predictable. whyItMatters":"The findings clarify that enforcing exactly‑once semantics largely depends on the tool contract and fault type, guiding designers on where to focus reliability mechanisms for LLM agents."

By Jiapeng Li
arXiv Computation and Language
Aug 27

When Stale Constraints Go Unchecked: Budgeted Verification Failures in Inherited Agent Memory

The paper investigates how agents that inherit consolidated memory can mistakenly rely on constraints that were once true but have since been superseded by newer records. By modeling supersession explicitly and limiting verification to two records, the study shows that native allocation often leads to stale-consistent decisions, while reallocating one verification slot to the critical provenance path markedly improves consistency. The results suggest that memory systems may need separate freshness or supersession signals beyond relevance to avoid such errors.

By Kazuki Nakayashiki
arXiv AI
Sep 25

Stale Does Not Mean Unsafe: Guard Precision for Tool-Using LLM Agents under Infrastructure State Races

The paper investigates how tool‑using language‑model agents can safely commit changes to infrastructure when external state may change between read and commit. By distinguishing invalidating races from predicate‑preserving and irrelevant ones, the authors evaluate three commit‑time guard granularities—global epoch, read‑set version, and semantic commit predicate—using a deterministic simulator and three quantized model families. The study finds that only the complete predicate guard consistently eliminates unsafe commits, while freshness‑based guards block a large proportion of benign races and model‑side signals fail to replace precise semantic enforcement.

By Zihao Zheng, Jiayu Long, Baichuan Li, Junyi Yao
arXiv Computation and Language
Oct 23

Memories That Outlive Their Reasons: Dependency-Tethered Memory for Tool-Using LLM Agents

The paper introduces Dependency‑Tethered Memory (Tether), a memory system for tool‑using LLM agents that records the exact versions of premises each verdict depends on. By withdrawing any verdict whose support has failed anywhere in the store, Tether reduces unsafe publications to 0.3% and cuts verification calls by 37% compared to naive fact memory, while maintaining similar recall. The study demonstrates that capturing dependencies is crucial for safe memory use, as weaker writers or delayed relation arrivals increase unsafe publication rates.

By Yiqi Wang, Jinqian Ju, Jiaqi Zhang, Zhangkai Wu, Yiqun Duan, Zequn Sun, Taotao Cai, Mingkai Zheng
arXiv AI
Sep 2

REVISE: Validity-Guided Recovery for Online Revisions in Agent Workflows

The paper introduces “Revise”, a runtime system that performs validity-guided, fine-grained recovery for online revisions in structured agent workflows. When a revision arrives, Revise intersects the change with recorded data and control dependencies, propagates the impact through the partially executed DAG, stops invalid work, preserves unaffected progress, and recomputes only the affected region. Experiments on real coding‑agent traces and LangGraph/LLMCompiler applications show that Revise matches a latest‑version oracle, reduces model calls by up to 56%, and improves service‑level objective goodput under load.

By Ruoling Qi, Xuaner Wu, Penghang Liu, Jian Chen, Yirui Liu
arXiv AI
Sep 3

The Memory Trust Gap: Capability-Dependent Failures in Persistent-Memory Agents

The paper investigates how persistent memory in AI agents can lead to over‑trust in stale facts, creating a "Memory Trust Gap" that worsens as model capability increases. Using a benchmark with Benefit and Safety suites across Qwen3 models of varying sizes, the authors show that larger models are more prone to harmful over‑trust, especially when metadata is absent or misleading. They also demonstrate that mitigation strategies such as exposing metadata or pre‑resolving conflicts improve accuracy, but the effectiveness depends on model size and dataset.

By Jundong Hu, Shekar Ramachandran
arXiv Machine Learning
Sep 7

Same Request, Different Answer: Quantization Amplifies Cache-Induced Divergence in LLM Serving

The paper investigates how prefix caching, a default optimization in open‑source LLM serving stacks, affects reproducibility when combined with weight quantization. Experiments on an eighty‑episode multi‑turn agentic tool‑use workload show that enabling the cache causes the agent’s trajectory to change in 36.2 % of episodes at 16‑bit precision and 75.0 % at 4‑bit precision, while disabling the cache yields perfectly reproducible runs. The study identifies specific cache‑related settings that drive run‑to‑run divergence and demonstrates that cached serving is deterministic only when the cache state is preserved, which is not the case in typical deployments.

By Aditi Patodiya
arXiv Computation and Language
Sep 23

MoM: Memory of Memory

arXiv:2609.25054v1 Announce Type: new Abstract: For a long-horizon LLM agent, the memory question is not what was once recorded but what \emph{currently holds}. Most designs answer it only indirectly...

By Bowen Qin, Yao Lu
arXiv AI
Sep 30

Boundary-State Control for Tool-Using Language-Model Agents: Commit-Time Consistency under State Drift

The paper introduces BSC‑R, a deterministic effect‑boundary mechanism that ties a single‑use commit authorization to the specific action and the semantic state that justified it, aiming to close the proposal‑to‑commit gap in tool‑using language‑model agents. Experiments on 2,847 AgentDojo episodes and 10,302 frozen proposals show that BSC‑R preserves the agent’s original behavior while rejecting unauthorized changes, and further tests on a boundary‑drift experiment and the CONTINUITY suite demonstrate high success rates in valid contexts and robust handling of replay and ambiguous cases. However, broader testing reveals that BSC‑R still allows a 25% invalid‑effect commit rate in a larger attack set, indicating that it provides scoped, not universal, safety.

By Wesley Shu