AIarXiv

Ranked by formulaVerdict: Notable

Harness-S: Learning from Sibling Harnesses for Generalizable Agent Training

Harness evolution from a common base exhibits Locality, Complementarity, and Nonstationarity: variants repair different failures, and their utility changes as the policy learns.

By Zhang, Jiao, Fang +8

Score████░░░░░░3.9

Caveats

  • Preprint; not yet peer reviewed.

VerdictWorth a reader's time today.

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Abstract

Harness evolution from a common base exhibits Locality, Complementarity, and Nonstationarity: variants repair different failures, and their utility changes as the policy learns. Rather than seeking a universally superior harness, we introduce Harness-S to selectively rescue failures of a base execution system through sibling harnesses and transfer the resulting capabilities into a single policy that remains effective under the original harness. Directional Harness Evolution develops specialized sibling harnesses along distinct repair directions, forming a reusable Sibling Harness Pool that remains fixed during policy training. Complementary Harness Rescue Training invokes this pool only when all initial attempts under the base harness fail. The same policy generates fresh rollouts under selected auxiliary harnesses, and these trajectories replace the failed group for reinforcement learning. An Adaptive Harness Router selects the Top-k variants using Harness Behavior Profiles and voting across multiple LLMs. Policy-aware profile re-anchoring refreshes this evidence as the policy learns. Across AppWorld, SWE-Gym, and DBBench, the trained policy substantially outperforms policy-only training when returned to the original base harness. Behavioral analyses and held-out cases support the transfer of harness-elicited behaviors into the policy itself. Reusing the router for Rank-1 inference provides additional gains at the same executor rollout count.

Kangning Zhang, Wenxiang Jiao, Bowen Fang, Shuai Shao, Jiachen Zhu, Rong Shan, Shijian Wang, Hao Wang, Yuan Lu, Weiwen Liu, Weinan Zhang

The editor's rubric

Heuristic review

Leverage4 / 5
A general-purpose tool used across several fields (Adam, ResNet, LoRA, next-generation sequencing).
24% of this desk’s rubric
Magnitude3 / 5
Large gain: roughly 2x, or a clear new state of the art on a hard, unsaturated problem.
18% of this desk’s rubric
Evidence3 / 5
Solid: multiple benchmarks or cohorts, ablations, fair baselines, released code or data.
14% of this desk’s rubric
Novelty3 / 5
A genuinely new approach to an open problem.
16% of this desk’s rubric
Trajectory2 / 5
Some room to improve with obvious engineering.
18% of this desk’s rubric
Stakes2 / 5
Benefits a professional community (practitioners, clinicians, engineers).
10% of this desk’s rubric

Editor’s rationale

Heuristic triage from title and abstract text only, not a reading of the paper. Cues found: method (we propose); breadth (general-purpose); gains (outperforms); novelty (alternative to status quo); verification (held-out test, code released); stakes (general AI).

How the score was computed

rank-2026-10-18

Score████░░░░░░3.9

Score = 10 × (65% × adjusted merit / 10 + 25% × attention + 10% × freshness)

Desks place stronger verdicts first, then use this score to order work within the same verdict.

Merit
5.9 / 10
Weighted rubric, evidence-gated.
Adjusted merit
4.8 / 10
Shrunk toward the desk prior by editor confidence (42%).
Attention
0%
Citations, upvotes, points, mentions.
Freshness
78%
Half-life decay since publication.

No attention signals recorded yet.

The record

  • Reviewed by heuristic-v10 on Nov 4, 2026, 02:05 UTC. Paper type: method.
  • Categories: cs.AI
  • BRIEF, No.4 in the Artificial Intelligence edition of November 4, 2026.