The Epistemics of Agent Memory: Measuring, and Governing, the Consolidation Decision in Long-Horizon LLM Agents
Organizations: All experiments in this program were designed, executed, and adversarially verified by the PRIMA multi-agent research-and-verification system [1] under the authors’ direction.
Abstract
Long-horizon LLM agents must convert accumulated experience into durable memory, deciding what to keep, compress, abstract into reusable skills and rules, or forget. We report a four-phase research program on this consolidation problem whose central finding is a shift in what is measured: from how much an agent remembers, to whether its consolidation decisions are any good, to whether those decisions can be trusted. Phase 1 learns episodic boundaries from agent traces by downstream utility; an honest near-miss (oracle correlation 0.691 vs a 0.70 bar) whose lasting output is a three-gate anti-leakage protocol. Phase 2 learns when to promote experience and to which abstraction level under a token budget, achieving a verified +22.7% task-success improvement with 7x compression, but exposing a degenerate-forgetting failure and a distribution-shift failure mode we name lambda-prevalence coupling. Phase 3 introduces ConsolidationBench, an oracle-by-construction benchmark that scores consolidation decisions against a known optimum on three non-circular axes; production retrieval systems retain information yet score zero on cross-level transfer. Phase 4 introduces governed consolidation: the decision wrapped in poison-resistance, reversibility, and auditability guarantees with a quality gate. Governance is statistically distinct from the quality score (; partial ; identical-quality policies differ threefold in governance), so the contribution survives independently of the metric's external validity. On that question we report a resolved negative: after a graded-reuse redesign removed a structural ceiling, a two-benchmark study with 2,532 real answer cells finds the quality score does not predict real transfer accuracy (pooled Spearman , n = 12, CI spanning zero). An adversarial self-critique pass cleared the final claim set with zero surviving overclaims.
Figures & tables
| Method | Boundary F1 | Oracle Corr. | Task Success | Proc. Reuse |
|---|---|---|---|---|
| Oracle | 1.000 | 1.000 | 0.900 | 0.691 |
| BoundaryLearner | 0.808 | 0.691 | 0.679 | 0.535 |
| Bayesian Surprise | 0.895 | 0.315 | 0.705 | 0.554 |
| Fixed Interval | 0.622 | 0.235 | 0.641 | 0.508 |
| Policy | Success | RetN | Compression | Transfer | CQS 0 | CQS |
|---|---|---|---|---|---|---|
| fixed_L2 (best) | 0.303 | 0.480 | 7.40 | 0.233 | 0.336 | 0.585 |
| learned_policy | 0.368 | 0.582 | 7.37 | 0.167 | 0.291 | 0.552 |
| mem0_style | 0.335 | 0.531 | 7.43 | 0.000 | 0.000 | 0.159 |
| simplemem_style | 0.306 | 0.485 | 7.53 | 0.000 | 0.000 | 0.152 |
| fixed_L1 | 0.274 | 0.434 | 7.47 | 0.000 | 0.000 | 0.144 |
| retrieval_only | 0.265 | 0.418 | 7.36 | 0.000 | 0.000 | 0.141 |
| Guarantee | Measurement | Medium | Hard |
|---|---|---|---|
| G1 Poison-resistance | false rules admitted | 0 | 0 |
| G2 Reversibility | rollback recovery (0 1 contrast) | 1.0 | 1.0 |
| G3 Auditability | ledger completeness | 1.0 | 1.0 |
| G4 Quality gate | CQS 0 retained | 0.622 | 0.475 |
| Phase | What the adversarial pass caught / enforced |
|---|---|
| 1 | Anti-leakage protocol established (provenance, probe, count-matched gates); the detector’s near-miss reported as a negative, not rounded up. |
| 2 | Degenerate forgetting exposed (high precision via near-total inaction); –prevalence coupling root-caused; integrity gates re-passed. |
| 3 | Headroom gate (benchmark sensitivity proven before training); non-circularity verified ( ); a -sweep sensitivity correction and three overclaims (leaderboard-champion wording, oracle-gap size, stale non-circularity values) caught and fixed. |
| 4 | Governance-by-inaction exploit caught (forced the mandatory G4 binding); G2’s constructed-variant ease hedged; a tie-handling statistical error in the validity caught and corrected; claims, zero surviving overclaims, three hedges. |