STALE: Can LLM Agents Know When Their Memories Are No Longer Valid?

AuthorsHanxiang Chao, Yihan Bai, Rui Sheng et al.

arXiv 20262026

TL;DR

STALE uses a three-dimensional probing framework over 400 implicit-conflict scenarios to show CUPMEM’s write-side state adjudication reaches 68.0% overall accuracy where other systems stay below 55.2%.

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THE PROBLEM

Implicit conflicts leave agents stuck at 55.2% accuracy

STALE shows that even the best evaluated model, Gemini-3.1-pro, reaches only 55.2% overall accuracy on implicit-conflict resolution.

In realistic long-term personalization, this means LLM agents keep stale memories, accept false premises, and produce unsafe or incoherent assistance.

HOW IT WORKS

STALE and CUPMEM — latent state tracking with write-side adjudication

STALE structures evaluation around State Resolution, Premise Resistance, and Implicit Policy Adaptation, while CUPMEM adds write-side belief updating and topology-triggered belief propagation.

You can think of STALE as a stress test for a user’s evolving “state RAM,” and CUPMEM as a card catalog that rewrites or retires cards whenever new evidence arrives.

This explicit adjudication lets CUPMEM retire outdated beliefs before retrieval, something a plain context window or naive RAG stack cannot enforce.

DIAGRAM

Three dimensional probing over implicit conflicts

This diagram shows how STALE probes State Resolution, Premise Resistance, and Implicit Policy Adaptation over Type I and Type II conflicts.

DIAGRAM

STALE dataset generation pipeline

This diagram shows how STALE constructs conflict scenarios from base states, adversarial conflicts, quality control, and haystack packaging.

PROCESS

How STALE Handles a Conflict Scenario Lifecycle

  1. 01

    Base State Formulation

    STALE samples a user attribute from the topic ontology and uses Base State Formulation to generate an earlier observation mo anchoring a clear belief.

  2. 02

    Adversarial Conflict Generation

    Using Adversarial Conflict Generation, a Logic Attacker writes a later observation mn that creates Type I or Type II implicit conflict without explicit negation.

  3. 03

    Quality Control

    In Quality Control, an LLM judge filters candidate pairs, enforcing Belief Incompatibility and Non explicit Invalidation before STALE accepts the scenario.

  4. 04

    Multi turn Dialogue Packaging

    STALE wraps mo and mn into multi turn sessions, inserts them into a long context haystack with distractors, and attaches SR, PR, and IPA probes.

KEY CONTRIBUTIONS

Key Contributions

  • 01

    Latent user state tracking

    STALE formalizes conversational memory as latent user state tracking with implicit conflict defined by Belief Incompatibility and Non explicit Invalidation, across 400 scenarios and 1,200 queries.

  • 02

    Three dimensional probing framework

    STALE introduces State Resolution, Premise Resistance, and Implicit Policy Adaptation probes, revealing that Gemini 3.1 pro reaches only 55.2% overall accuracy.

  • 03

    CUPMEM prototype for state adjudication

    CUPMEM adds write side belief updating and propagation aware search, boosting GPT 4o mini from 8.7% to 68.0% overall accuracy on STALE.

RESULTS

By the Numbers

Overall

68.0%

+12.8 over Gemini-3.1-pro

Type I PR

78.0%

vs GPT-4o-mini backbone at 0.0%

Type II PR

75.0%

premise resistance gain over Gemini-3.1-pro at 14.0%

Type I SR

91.0%

close to Gemini-3.1-pro at 92.0% with smaller backbone

STALE evaluates implicit conflict handling over 400 scenarios and 1,200 queries, measuring SR, PR, and IPA for Type I and Type II conflicts. CUPMEM’s 68.0% overall accuracy shows that explicit state adjudication can close much of the gap left by Gemini-3.1-pro’s 55.2% on the same benchmark.

BENCHMARK

By the Numbers

STALE evaluates implicit conflict handling over 400 scenarios and 1,200 queries, measuring SR, PR, and IPA for Type I and Type II conflicts. CUPMEM’s 68.0% overall accuracy shows that explicit state adjudication can close much of the gap left by Gemini-3.1-pro’s 55.2% on the same benchmark.

BENCHMARK

Main results on STALE — Overall accuracy comparison

Overall accuracy on STALE across closed source LLMs, open source LLMs, memory frameworks, and CUPMEM.

KEY INSIGHT

The Counterintuitive Finding

STALE shows that Gemini 3.1 pro hits 92.0% on Type I State Resolution but only 30.0% on Type I Premise Resistance.

This breaks the assumption that once a system can recognize stale information explicitly, it will automatically reject user queries that embed the same stale premise.

WHY IT MATTERS

What this unlocks for the field

STALE and CUPMEM make it possible to test and enforce when LLM agents should retire or revise long term personalized memories.

Builders can now design agents that resist stale premises, propagate updates across related attributes, and maintain coherent user state over 150K token histories.

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