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LLM-as-a-Verifier: A General-Purpose Verification Framework

Source

arXiv

arxiv.org/abs/2607.05391v1

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Plain-Language Brief

The paper introduces LLM-as-a-Verifier, a general-purpose verification framework that provides fine-grained feedback to improve the accuracy of agentic tasks. The framework scales across multiple dimensions for better separation between positive and negative solutions, and it achieves state-of-the-art performance on various benchmarks.

What the Document Says

  • The work proposes LLM-as-a-Verifier, a general-purpose verification framework.
  • The framework provides fine-grained feedback for agentic tasks without requiring additional training.
  • Instead of producing discrete scores, the framework computes the expectation over the distribution of scoring token logits to generate continuous scores.
  • Scaling the scoring granularity leads to better separation between positive and negative solutions.
  • Scaling repeated evaluation and criteria decomposition lead to additional gains in verification accuracy.
  • The paper introduces a cost-efficient ranking algorithm for selecting the best solution among candidates using the verifier's continuous scores.
  • LLM-as-a-Verifier achieves state-of-the-art performance on various benchmarks: Terminal-Bench V2 (86.5%), SWE-Bench Verified (78.2%), RoboRewardBench (87.4%), and MedAgentBench (73.3%).
  • The fine-grained signals from LLM-as-a-Verifier can serve as a proxy for estimating task progress.
  • An extension for Claude Code is built to monitor and improve agentic systems.
  • The paper suggests that LLM-as-a-Verifier can provide dense feedback for reinforcement learning, improving the sample efficiency of SAC and GRPO on robotics and mathematical reasoning benchmarks.

Key Concepts Mentioned

  • LLM-as-a-Verifier
  • verification framework
  • agentic tasks
  • score granularity
  • repeated evaluation
  • criteria decomposition
  • benchmark results
  • fine-grained signals

Claims Made by the Document

  • LLM-as-a-Verifier provides fine-grained feedback for agentic tasks without additional training.
  • Scaling the scoring granularity leads to better separation between positive and negative solutions.
  • Scaling repeated evaluation and criteria decomposition lead to additional gains in verification accuracy.
  • LLM-as-a-Verifier achieves state-of-the-art performance on various benchmarks.

Evidence Used

  • The introduction of LLM-as-a-Verifier.
  • The description of how the framework computes continuous scores and scales across dimensions.
  • The results from benchmark tests showing state-of-the-art performance.

Methods / Approach

UNKNOWN

Limitations Stated by the Authors

UNKNOWN

Limitations Noted by the Agent

Agent interpretation — not from the source.

UNKNOWN

Open Questions

UNKNOWN

Notes for Future Q&A

May include interpretation. Labeled where it does.

UNKNOWN

Raw Abstract / Excerpt

Scaling pre-training, post-training, and test-time compute have become the central paradigms for improving the capabilities of LLMs. In this work, we identify verification, the ability to determine the correctness of a solution, as a new scaling axis. To unlock this and demonstrate its effectiveness, we introduce LLM-as-a-Verifier, a general-purpose verification framework that provides fine-grained feedback for agentic tasks without requiring additional training. Unlike standard LM judges that prompt LLMs to produce discrete scores for candidate solutions, LLM-as-a-Verifier computes the expectation over the distribution of scoring token logits to generate continuous scores. This probabilistic formulation enables verification to scale along multiple dimensions: (1) score granularity, (2) repeated evaluation, and (3) criteria decomposition. In particular, we show that scaling the scoring granularity leads to better separation between positive and negative solutions, resulting in more calibrated comparisons. Moreover, scaling repeated evaluation and criteria decomposition consistently lead to additional gains in verification accuracy through variance and complexity reduction. We further introduce a cost-efficient ranking algorithm for selecting the best solution among candidates using the verifier's continuous scores. LLM-as-a-Verifier achieves state-of-the-art performance on Terminal-Bench V2 (86.5%), SWE-Bench Verified (78.2%), RoboRewardBench (87.4%), and MedAgentBench (73.3%). Beyond verification, the fine-grained signals from LLM-as-a-Verifier can also serve as a proxy for estimating task progress. We build an extension for Claude Code, enabling developers to monitor and improve their own agentic systems. Finally, we show that LLM-as-a-Verifier can provide dense feedback for RL, improving the sample efficiency of SAC and GRPO on robotics and mathematical reasoning benchmarks.