What Is a Skill Worth? Structure-Aware Shapley Valuation of Agent Skills

Title:What Is a Skill Worth? Structure-Aware Shapley Valuation of Agent Skills

Abstract:Agent skills are increasingly optimized by automated feedback loops, producing long structured artifacts whose internal value remains unclear. We study skill valuation: assigning credit to the internal units of a fixed skill, such as rules, examples, scripts, and heuristics, under a fixed agent and held-out task distribution. Skill valuation differs from data or prompt-span valuation because skill units are structured: they may depend on other units, belong to a document hierarchy, trigger agent behavior, and consume limited prompt context. We introduce SkillSV, a structure-aware Shapley-style framework for skill valuation. SkillSV compiles a skill into units, dependencies, and hierarchy, so that only valid counterfactual skills are evaluated. It uses paired deletion and length-neutral padding to separate content value from context cost, and estimates the resulting values with a rollout-budgeted estimator for noisy agent evaluations. On four agentic benchmarks, we assess the faithfulness, actionability, and explanation of SkillSV: it recovers unit interactions, preserves aggregate skill lift, and guides safe pruning and compression.

Artificial Intelligence (cs.AI)

arXiv:2608.04562 [cs.AI]

(or arXiv:2608.04562v1 [cs.AI] for this version)

https://doi.org/10.48550/arXiv.2608.04562 Focus to learn more arXiv-issued DOI via DataCite (pending registration)

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