AgentCL: Toward Rigorous Evaluation of Continual Learning in Language Agents

AuthorsYiheng Shu, Bernal Jiménez Gutiérrez, Saisri Padmaja Jonnalagedda et al.

arXiv 20262026

TL;DR

AGENTCL uses controlled compositional task streams plus MEMPROBE’s multi-view memory probing to expose large plasticity gains (e.g., +21.9 pp on CodeEval-Pro) that naive streams hide.

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THE PROBLEM

Continual agents lack reusable experience and clear transfer metrics

Language agents spend substantial inference time on tasks, yet experience acquired in one episode is often underutilized in future episodes.

Existing benchmarks use naive task streams and average accuracy, making it hard to see plasticity, stability, and what is actually being reused over time.

HOW IT WORKS

AGENTCL and MEMPROBE — controlled streams plus multi view memory

AGENTCL introduces naive streams, compositional streams, and a two pass protocol, while MEMPROBE builds interaction memory, insight memory, and skill memory with validation.

Think of AGENTCL as a carefully scripted curriculum and MEMPROBE as a librarian that files episodes as raw logs, distilled lessons, and reusable code snippets.

This design lets AGENTCL measure plasticity, stability, and generalization in ways a plain context window or uncontrolled task order cannot.

DIAGRAM

Two pass continual learning protocol in AGENTCL

This diagram shows how AGENTCL runs first pass and second pass over the same task stream to compute Plasticity Gain and Stability Gain.

DIAGRAM

AGENTCL evaluation pipeline across task streams

This diagram shows how AGENTCL builds naive and compositional streams, runs two pass evaluation, and then tests held out tasks.

PROCESS

How AGENTCL Handles a Task Stream Episode

  1. 01

    Task Streams

    AGENTCL constructs naive and compositional task streams where later tasks may reuse earlier sub solutions, evidence, or workflows.

  2. 02

    Two Passes

    AGENTCL runs a first pass with read write memory and a second pass with frozen memory to obtain Fi and Si for each task.

  3. 03

    Transfer Metrics

    AGENTCL computes Plasticity Gain PGi = Fi − Bi, Stability Gain SGi = Si − Fi, and Generalization Gain GGj = Hj − Bj.

  4. 04

    MEMPROBE Loop

    MEMPROBE performs retrieve solve consolidate, building interaction memory, insight memory, and skill memory while filtering unreliable experiences.

KEY CONTRIBUTIONS

Key Contributions

  • 01

    AGENTCL evaluation framework

    AGENTCL formalizes continual learning in agents with naive versus compositional task streams and explicit Plasticity Gain, Stability Gain, and Generalization Gain metrics.

  • 02

    Controlled task streams

    AGENTCL constructs compositional streams on CodeEval-Pro and BrowseComp+ where 48 and 308 subtasks respectively precede 48 and 100 complex tasks.

  • 03

    MEMPROBE memory probing

    AGENTCL introduces MEMPROBE with interaction memory, insight memory, and skill memory plus validation, achieving large compositional PG like +21.9 pp on CodeEval-Pro.

RESULTS

By the Numbers

Average accuracy MMLU Pro 1st Pass

82.7%

+4.0 over ReAct

Average accuracy MMLU Pro 2nd Pass

83.0%

+4.3 over ReAct

Std Dev accuracy MMLU Pro 1st Pass

1.7

method separation across ReAct, ExpRAG, ReMem, MEMPROBE

Std Dev accuracy MMLU Pro 2nd Pass

1.8

shows naive streams compress differences

These numbers come from the naive MMLU-Pro streams in AGENTCL, where each domain has 100 tasks and memory is maintained separately. The results show MEMPROBE slightly improves over ReAct, while small standard deviations highlight that naive streams provide limited discriminative power for continual learning.

BENCHMARK

By the Numbers

These numbers come from the naive MMLU-Pro streams in AGENTCL, where each domain has 100 tasks and memory is maintained separately. The results show MEMPROBE slightly improves over ReAct, while small standard deviations highlight that naive streams provide limited discriminative power for continual learning.

BENCHMARK

Accuracy on naive MMLU Pro streams (Table 2)

Average accuracy across economics, engineering, and philosophy on the naive MMLU-Pro stream first pass.

KEY INSIGHT

The Counterintuitive Finding

On BrowseComp+, compositional streams yield accuracy standard deviations of 14.9 and 16.0, while naive streams show only 2.3 and 5.7 across methods.

This is surprising because many assume streaming tasks from the same domain is enough, but AGENTCL shows explicit compositional structure is crucial for revealing plasticity differences.

WHY IT MATTERS

What this unlocks for the field

AGENTCL lets researchers precisely measure how language agents accumulate and reuse experience using MEMPROBE’s validated interaction, insight, and skill memories.

Builders can now design and debug continual learning agents with clear plasticity, stability, and generalization signals instead of relying on opaque average scores from uncontrolled task streams.

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