SkillLift paper reports 40–70% lower token cost for evolving agent skills
DAIR.AI highlighted a paper on SkillLift, a method for evolving agent skill prompts without running a full agent rollout to score every candidate revision. SkillLift trains a rubric to agree with real outcomes on which of two skills is better, on the grounds that ranking needs fewer oracle runs than predicting each score.
An inner loop revises skills against a frozen rubric at no rollout cost. An outer loop spends a few real rollouts to re-align the rubric by rank correlation. The post says rollout cost is why skill self-evolution usually only patches observed failures.
On SkillsBench and WildClawBench (147 tasks) with three models, SkillLift reportedly beat SkillOpt and CoEvoSkills in all six combinations, even when those baselines received twice the token budget, and reached target performance with 40 to 70% fewer tokens. Paper: https://academy.dair.ai/papers/skilllift-learning-dense-rubrics-from-sparse-oracles-for-efficient-skill-evoluti-2609.15396