RRSI: Regularized Recursive Self-Improvement of Agent Harnesses

TL;DR

RRSI enhances agent capabilities through regularized recursive self-improvement, excelling in cross-domain benchmarks.

cs.LG 🔴 Advanced 2026-09-22 8 views
Peng Xia Rujun Han Zifeng Wang Yanfei Chen Yufan Zhang Yoonho Lee Chengsong Huang Han Yu Zhongying CuiZhu Yifei Ming Huaxiu Yao Burak Gokturk Tomas Pfister Chen-Yu Lee
AI machine learning self-improvement regularization agent systems

Key Findings

Methodology

RRSI incorporates regularization principles into recursive self-improvement by constraining candidate proposal and selection. The proposer uses a temporally annealed budget to limit edits and encourage unexplored trajectories. The selector employs a critic and pruner to screen benchmark-specific proposals and remove insignificant changes.

Key Results

  • RRSI achieved up to 14.1 points improvement on eight benchmarks and up to 4.7 points on five out-of-distribution benchmarks, while reducing policy token usage by 30%.
  • In engineering design tasks, RRSI achieved a 24.3% relative improvement.
  • RRSI consistently outperformed baseline methods on all out-of-distribution datasets.

Significance

RRSI addresses the overfitting issue in agent systems, enhancing cross-domain task generalization, with significant academic and industrial impact.

Technical Contribution

RRSI introduces regularization mechanisms to limit overfitting during proposal and selection, offering new theoretical guarantees and engineering possibilities.

Novelty

RRSI is the first to apply regularization principles to recursive self-improvement in agent systems, significantly reducing overfitting compared to existing methods.

Limitations

  • RRSI may underperform on tasks requiring extensive domain-specific knowledge.
  • Limited computational resources may hinder RRSI's effectiveness.

Future Work

Future research could explore RRSI's application to more task types and optimize its regularization mechanisms for improved efficiency.

AI Executive Summary

RRSI enhances agent systems through regularized recursive self-improvement, addressing overfitting issues. Existing methods perform well on training sets but often fail on out-of-distribution tasks. RRSI limits candidate proposal edits and selection criteria, using a critic and pruner to reduce overfitting risks. Experimental results show RRSI excels across multiple benchmarks, significantly enhancing cross-domain task generalization. While RRSI may underperform on specific tasks, its innovative regularization mechanisms offer new possibilities for agent system self-improvement. Future research could further optimize RRSI's regularization mechanisms and explore its application to more task types.

Deep Analysis

Background

Agent systems' capabilities are largely determined by their harness, including prompts, control flow, tool interfaces, memory, and context management. Existing methods automate harness improvement through iterative proposal and selection of component edits, but often lead to overfitting.

Core Problem

Agent systems perform well on training sets but often fail on out-of-distribution tasks, with overfitting being the primary issue.

Innovation

RRSI enhances recursive self-improvement through regularization, limiting candidate proposal edits and selection criteria, using a critic and pruner to reduce overfitting risks.

Methodology

  • �� Proposer uses a temporally annealed budget to limit candidate proposal edits.
  • �� Selector employs a critic and pruner to screen benchmark-specific proposals and remove insignificant changes.
  • �� Regularization mechanisms encourage unexplored trajectories.

Experiments

Experiments were conducted on eight benchmarks covering coding, agentic workspace, and engineering design tasks, evaluating RRSI's generalization capabilities.

Results

RRSI achieved up to 14.1 points improvement on eight benchmarks and up to 4.7 points on five out-of-distribution benchmarks, while reducing policy token usage by 30%.

Applications

RRSI can be used to enhance agent systems' generalization capabilities, suitable for scenarios requiring cross-domain tasks.

Limitations & Outlook

RRSI may underperform on tasks requiring extensive domain-specific knowledge.

Plain Language Accessible to non-experts

Imagine a kitchen where the chef has a fixed recipe but can improve the dish by adjusting spices and cooking methods. RRSI is like the chef improving the dish by limiting the number of spices and selection criteria to avoid over-reliance on any one spice.

ELI14 Explained like you're 14

Imagine you're playing a game with a character that has many skills. RRSI is like a system in the game that helps your character become stronger by limiting skill usage and selection to avoid over-reliance on any one skill.

Glossary

Regularization

A method to reduce overfitting by limiting model complexity, enhancing generalization.

Used in RRSI to limit candidate proposal edits and selection criteria.

Recursive Self-Improvement

A process of automating agent harness improvement through iterative proposal and selection of component edits.

RRSI enhances agent systems through regularized recursive self-improvement.

Critic

A mechanism to screen benchmark-specific proposals, helping the selector remove insignificant changes.

Used in RRSI's selection process.

Pruner

A mechanism to remove insignificant changes, helping the selector optimize candidate proposals.

Used in RRSI's selection process.

Temporally Annealed Budget

A mechanism to limit candidate proposal edits, encouraging unexplored trajectories.

Used in RRSI's proposal process.

Open Questions Unanswered questions from this research

  • 1 How can RRSI's regularization mechanisms be further optimized for efficiency?
  • 2 What is the potential of RRSI's application to more task types?

Applications

Immediate Applications

Agent System Optimization

RRSI can be used to optimize agent system harnesses, enhancing cross-domain task generalization.

Long-term Vision

Intelligent System Self-Improvement

RRSI offers new possibilities for intelligent system self-improvement, potentially applicable to more fields in the future.

Abstract

An LLM agent's capability is largely magnified by its harness, namely the prompts, control flow, tooling, memory, and context management surrounding the frozen backbone model. Recent methods increasingly automate this process by iteratively proposing and selecting component-wise edits of an agent harness, practically establishing a form of recursive self-improvement (RSI) at the agent-system level. However, such recursive evolution may overfit by memorizing the training tasks, showing large in-distribution gains that shrink or even vanish on out-of-distribution benchmarks. We introduce Regularized Recursive Self-Improvement of Agent Harnesses (RRSI), which incorporates the principles of regularizations into harness self-improvement by constraining the evolution candidate proposal and selection. The proposer operates with a temporally annealed budget, limiting how many edits a candidate can bundle, and it encourages unexplored trajectories based on evolution history. The selector is equipped with a critic and a pruner: the critic screens benchmark-specific proposals, while the pruner, removes changes that are too small, too expensive, or no longer useful. Together these constraints favor reusable agent mechanisms over benchmark-specific ones or even noises. Across eight benchmarks spanning coding, agentic workspace and engineering design tasks, RRSI gains up to 14.1 points on the split it evolves against and up to 4.7 points on the five out-of-distribution benchmarks, while producing a harness that runs on 30% fewer policy tokens than the unregularized evolution. Code is available at https://github.com/google-research/rrsi and project page is https://regularized-rsi.com/.

cs.LG cs.AI cs.CL