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arxiv: 2605.23657 · v2 · pith:H5ICOP4Snew · submitted 2026-05-22 · 💻 cs.CL

OpenSkillEval: Automatically Auditing the Open Skill Ecosystem for LLM Agents

Jiahao Ying , Boxian Ai , Wei Tang , Siyuan Liu , Yixin Cao This is my paper

Pith reviewed 2026-05-25 04:15 UTC · model grok-4.3

classification 💻 cs.CL
keywords LLM agentsskill evaluationopen-source skillsagent frameworksdynamic task generationbenchmarkingskill augmentation
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The pith

Many publicly popular skills for LLM agents do not consistently outperform base agents without skills.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper presents OpenSkillEval as a framework that automatically builds realistic task instances from live real-world artifacts in five application areas to test how skills interact with different LLM models and agent setups. It evaluates over 600 tasks against 30 open-source skills and finds that simply having skills available does not ensure they get used effectively. The benefit of adding skills turns out to depend heavily on which model and framework is underneath, and many popular skills add little or no advantage over running the base agent alone. This matters for anyone trying to pick or build skills because the open ecosystem is expanding without clear signals on which ones actually help in practice. The work pushes for ongoing, task-grounded testing instead of relying on static benchmarks.

Core claim

OpenSkillEval automatically constructs realistic task instances from evolving real-world artifacts across five categories of downstream applications and collects community-contributed skills for controlled comparison under unified settings. Using more than 600 dynamically generated task instances and 30 open-source skills, the evaluation shows that skill availability does not guarantee effective skill usage, that the benefit of skill augmentation depends strongly on both the underlying model and the agent framework, and that many publicly popular skills do not consistently outperform base agents without skills.

What carries the argument

OpenSkillEval, an automatic evaluation framework that dynamically generates task instances from real-world artifacts for side-by-side testing of skill-augmented LLM agent systems.

If this is right

  • Skill selection must be done per model and per agent framework rather than treating skills as plug-and-play improvements.
  • Skill authors should test their instructions across multiple base models instead of a single one.
  • Agent frameworks need better mechanisms to decide when to invoke a skill versus running without one.
  • The open skill ecosystem would benefit from continuous re-evaluation as models and artifacts evolve.
  • Base agents without skills can remain competitive choices when cost or reliability is prioritized.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • Platforms hosting skills could add automated quality checks that rerun evaluations whenever new models appear.
  • The same generation approach could be applied to other agent domains such as code editing or scientific workflows to test generality.
  • If skills are to be treated as modular components, the field may need interface standards that reduce model-specific tuning.
  • The observed variance suggests that some skills might be better reframed as lightweight prompt templates rather than full workflows.

Load-bearing premise

The dynamically generated task instances drawn from real-world artifacts are realistic enough proxies for actual downstream user tasks.

What would settle it

A controlled study in which real users complete the same categories of tasks with and without the evaluated skills and report measurably higher success rates or lower effort for the popular skills would falsify the claim that many skills fail to outperform base agents.

Figures

Figures reproduced from arXiv: 2605.23657 by Boxian Ai, Jiahao Ying, Siyuan Liu, Wei Tang, Yixin Cao.

Figure 1
Figure 1. Figure 1: Overview of the OpenSkillEval framework. The framework supports automatic test case [PITH_FULL_IMAGE:figures/full_fig_p003_1.png] view at source ↗
Figure 3
Figure 3. Figure 3: Trajectory-level analysis of how different agent access and follow provided skills. [PITH_FULL_IMAGE:figures/full_fig_p006_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: Token usage across agents and tasks. Mean completion tokens (left) and uncached input [PITH_FULL_IMAGE:figures/full_fig_p008_4.png] view at source ↗
Figure 5
Figure 5. Figure 5: Skill performance versus cost across tasks and agent systems. Each subplot corresponds to [PITH_FULL_IMAGE:figures/full_fig_p009_5.png] view at source ↗
Figure 6
Figure 6. Figure 6: Impact of skills on stylistic diversity relative to the [PITH_FULL_IMAGE:figures/full_fig_p010_6.png] view at source ↗
Figure 7
Figure 7. Figure 7: Comparison of skill-augmented and no-skills settings on reasoning intensive tasks. Cost Analysis. Beyond their impact on artifact quality, we further analyze the cost implications of skill augmentation. As shown in [PITH_FULL_IMAGE:figures/full_fig_p013_7.png] view at source ↗
Figure 8
Figure 8. Figure 8: Web-based interface for human evaluation of generated task instances. [PITH_FULL_IMAGE:figures/full_fig_p023_8.png] view at source ↗
Figure 9
Figure 9. Figure 9: Artifact inspection interface used in human evaluation. The system provides task-specific [PITH_FULL_IMAGE:figures/full_fig_p024_9.png] view at source ↗
Figure 10
Figure 10. Figure 10: Skill performance versus cost across tasks and agent systems. Each subplot corresponds [PITH_FULL_IMAGE:figures/full_fig_p025_10.png] view at source ↗
Figure 11
Figure 11. Figure 11: Impact of web design skills on stylistic diversity relative to the [PITH_FULL_IMAGE:figures/full_fig_p025_11.png] view at source ↗
read the original abstract

Skills, i.e., structured workflow instructions distilled for large language models (LLMs), are becoming an increasingly important mechanism for improving agent performance on real-world downstream tasks. However, as the open-source skill ecosystem rapidly expands, it remains unclear how different models and agent frameworks interact with skills, how to evaluate skill quality, and how users should select skills under practical cost-performance trade-offs. In this paper, we present \textsc{OpenSkillEval}, an automatic evaluation framework for both skill-augmented agent systems and the skills themselves. Instead of relying on static benchmarks, \textsc{OpenSkillEval} automatically constructs realistic task instances from evolving real-world artifacts across five categories of downstream applications: presentation generation, front-end web design, poster generation, data visualization, and report generation. It further collects and organizes community-contributed skills for controlled comparison under unified task settings. Using more than 600 dynamically generated task instances and 30 open-source skills, we conduct a systematic evaluation of state-of-the-art models and agent frameworks. Our results show that skill availability does not guarantee effective skill usage, that the benefit of skill augmentation depends strongly on both the underlying model and the agent framework, and that many publicly popular skills do not consistently outperform base agents without skills. These findings highlight the need for dynamic, task-grounded evaluation and provide practical insights into the design, selection, and deployment of skills for LLM agents. Additional cases and benchmark resources are available on the project website: https://yingjiahao14.github.io/OpenSkillEval-Web/.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 2 minor

Summary. The paper introduces OpenSkillEval, an automatic evaluation framework that dynamically constructs over 600 task instances from real-world artifacts across five categories (presentation generation, front-end web design, poster generation, data visualization, report generation). It organizes 30 community-contributed open-source skills for controlled comparison against base agents using state-of-the-art models and frameworks, concluding that skill availability does not guarantee effective usage, that augmentation benefits depend strongly on the underlying model and agent framework, and that many popular skills fail to consistently outperform base agents without skills.

Significance. If the task instances prove representative, the work would offer timely empirical evidence on the practical limitations of the expanding open skill ecosystem for LLM agents, underscoring the value of dynamic, task-grounded evaluation over static benchmarks and supplying actionable insights for skill design and selection.

major comments (2)
  1. [Methods (task construction)] Methods (task construction): The central claims rest on 600+ dynamically generated instances derived from real-world artifacts, yet the manuscript describes no external validation (expert ratings, comparison to logged user sessions, or hold-out real tasks) to confirm that the automatic construction process yields faithful proxies for downstream user tasks; without this, observed non-improvements and model/framework interactions risk being artifacts of the generation procedure rather than general properties of the skill ecosystem.
  2. [Evaluation setup] Evaluation setup (§ on experimental design): No details are provided on statistical controls, variance estimation across task instances, or error analysis for the reported comparisons; this leaves the strength of the model- and framework-dependent interaction claims difficult to assess.
minor comments (2)
  1. [Abstract] The abstract and introduction would benefit from a brief explicit statement of the five task categories and the exact number of skills per category to improve readability.
  2. [Conclusion] Project website link is provided but the manuscript does not indicate whether the generated task instances and skill implementations are released as open resources.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for the constructive feedback. We address each major comment below and commit to revisions that directly strengthen the claims regarding task fidelity and statistical rigor.

read point-by-point responses

  1. Referee: [Methods (task construction)] The central claims rest on 600+ dynamically generated instances derived from real-world artifacts, yet the manuscript describes no external validation (expert ratings, comparison to logged user sessions, or hold-out real tasks) to confirm that the automatic construction process yields faithful proxies for downstream user tasks; without this, observed non-improvements and model/framework interactions risk being artifacts of the generation procedure rather than general properties of the skill ecosystem.

    Authors: We agree that external validation would further substantiate the representativeness of the generated tasks. The construction procedure directly ingests and adapts real-world artifacts (e.g., actual slide decks, web pages, and data tables) rather than synthesizing from scratch, which we argue already provides a stronger proxy than static benchmarks. Nevertheless, to address the concern explicitly, we will add a targeted expert validation study on a random subset of tasks in the revised manuscript. revision: yes

  2. Referee: [Evaluation setup] Evaluation setup (§ on experimental design): No details are provided on statistical controls, variance estimation across task instances, or error analysis for the reported comparisons; this leaves the strength of the model- and framework-dependent interaction claims difficult to assess.

    Authors: We acknowledge that the current manuscript omits explicit statistical controls and variance reporting. In the revision we will include (1) details of the statistical tests performed to assess model–framework–skill interactions, (2) per-category variance and confidence intervals across the 600+ instances, and (3) a qualitative error analysis highlighting representative failure modes. revision: yes

Circularity Check

0 steps flagged

No circularity: empirical evaluation independent of inputs

full rationale

The paper presents an empirical auditing framework that constructs task instances from external real-world artifacts and compares skill-augmented agents against base agents using community-contributed skills. No equations, fitted parameters renamed as predictions, self-definitional constructs, or load-bearing self-citations are present in the derivation of the central claims. Results are measured directly on held-out generated instances rather than reducing to the construction process by definition.

Axiom & Free-Parameter Ledger

0 free parameters · 0 axioms · 0 invented entities

Abstract-only review; no explicit free parameters, axioms, or invented entities are described.

pith-pipeline@v0.9.0 · 5814 in / 1065 out tokens · 26967 ms · 2026-05-25T04:15:58.017298+00:00 · methodology

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