When Should LLM Agents Forget? Memory Filtering Under Query-Critical Resolver Errors

Samarth Vinayaka


Abstract
LLM memory systems often filter facts classified as stale from the current prompt. We study this query-time context filtering, without deleting stored memories, in memory-conditioned question answering. Across three models on a synthetic benchmark, controlled label corruption moves hard-drop from gains of +0.186 to +0.230 at perfect resolution to losses of −0.176 to −0.181 at the lowest tested reliability. Paired targeted interventions show greater degradation from false-drop than false-keep; retaining evidence can still fail when incorrect labels steer generation. On one frozen 102/102 calibration/test query split, empirical policy selection using labeled calibration outcomes reaches 0.655 accuracy versus 0.641 for always hard-drop and 0.662 for test-informed oracle selection. A question-disjoint MemoryAgentBench replication is inconclusive: gain +0.03, 95% CI [−0.01, +0.08]. These results establish a controlled sensitivity mechanism, not generalization to long-horizon agents. Global-accuracy crossovers require gold labels and are model- and task-specific diagnostics. Context filtering should be cost-sensitive and validated on matched labeled data; label-free retention is an accuracy fallback under the tested errors, subject to separate privacy and retention requirements.
Anthology ID:
2026.realm-1.16
Volume:
Proceedings of the Second Workshop for REsearch on Agent Language Models (REALM 2026)
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Ehsan Kamalloo, Nicolas Gontier, Nikolai Rozanov, Maryam Hashemzadeh, Akhil Arora
Venues:
REALM | WS
SIG:
Publisher:
Association for Computational Linguistics
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Pages:
212–225
Language:
URL:
https://aclanthology.org/2026.realm-1.16/
DOI:
Bibkey:
Cite (ACL):
Samarth Vinayaka. 2026. When Should LLM Agents Forget? Memory Filtering Under Query-Critical Resolver Errors. In Proceedings of the Second Workshop for REsearch on Agent Language Models (REALM 2026), pages 212–225, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
When Should LLM Agents Forget? Memory Filtering Under Query-Critical Resolver Errors (Vinayaka, REALM 2026)
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PDF:
https://aclanthology.org/2026.realm-1.16.pdf