Same skill, +22 points for Claude Sonnet, +5.5 for Nemotron Nano
Notes on A Framework for Evaluating Agentic Skills at Scale (arXiv:2606.17819) — Maksim Shaposhnikov, Nicolas Fortuin, Simon Stipcich, Maria I. Gorinova, Amy Heineike, Robert S. Willoughby · June 2026
Note published · written by SkillFed’s research pipeline from the paper above · how these notes are made
AI-assisted notes · reviewed by SkillFed Agentic benchmarksAn automated pipeline turns any agent skill into a battery of executable tests. It reads the skill's content, provisions whatever the task needs — CLI tools, credentials, a specific runtime — drafts a realistic task description, and writes two hidden scoring rubrics, then runs a validation pass to confirm the task doesn't leak its own answer. Applied to 500 real-world skills pulled from public registries and sourced from roughly 100 organizations, including Anthropic, Google, ElevenLabs, and Shopify, the pipeline generated about 1,000 tasks. Each one was solved twice — once with the skill available, once without — across 19 proprietary and open-source model configurations spanning Claude, GPT, Gemini, GLM, DeepSeek, Kimi, MiniMax, Qwen, and Nemotron. That produced roughly 38,000 scored trajectories, graded on two separate rubrics: did the output actually work (goal completion), and did it follow the skill's encoded conventions (instruction-following).
Skill access reliably moves the needle, but by wildly different amounts. The aggregate score gain — the skill delta — ranges from +5.5 points for Nemotron 3 Nano 30B up to +22.1 for Claude Sonnet 4.6, and it comes almost entirely from instruction-following: goal completion was already high without a skill and climbs above 90% for most models once the skill is present, Nemotron being the one holdout. Frontier instruction-following scores cluster in the mid-to-high 80s (Opus 4.8 at 88.0, Opus 4.7 at 87.7, the open-weights GLM 5.1 at 85.0), while Kimi K2.6, MiniMax 2.7, and Qwen3-Coder-Next sit 25-30 points lower even with the skill in hand. Give a cheaper model the skill and it closes in on its flagship sibling: GLM 5.1 hits an overall score of 91.1, within 1.2-1.6 points of Opus 4.7's 92.3 and Opus 4.8's 92.7, at roughly a quarter of the per-scenario cost. The uplift is domain-dependent too — skills that encode concrete step-by-step workflows, like media file processing or security checklists, gain over +30 points, while skills that mainly state general best practices, like testing or scientific computing, gain closer to +17.
Key numbers
| Corpus scale | 500 skills → ~1,000 tasks → 19 models |
| Skill-driven score gain (range across models) | +5.5 to +22.1 pts |
| Instruction-following gap: frontier vs. mid-tier models | ~25-30 pts |
| Kimi K2.6 skill delta (recent model, low uptake) | +7.1 pts |
| Open-weight cost to near-match flagship quality | $0.89 vs. $3.94/scenario |
Skills related to this research
Related notes
- Forced to search a 34k-skill library instead of being handed the right one, agents' pass rate falls from 55.4% to 38.4% -- a hair above the 35.4% no-skill floor →
- 48% of the time, agents don't even read their own skill file →
- A 96,401-skill curated corpus lifts agent pass rates +7.5pp — until coverage runs out →
- 40,285 Skills Later, Supply Still Doesn't Match Demand →
- Agent-skill catalogs already top 700,000 entries — curation hasn't caught up →
- LLM-Written Agent Skills Add Zero Pass-Rate Gain — Self-Diagnosis Closes Up to 67% of the Gap to Human Authors →
- One Feedback Pass Takes Skill-Chain Decomposition From 51% to 68% Accuracy →
- Letting a robot invent its own practice tasks adds 20.6 points of task success →
- Compose agents from skills, not fixed roles: +2 points over the best topology-only baseline, only a 0.96-point dip when the skill library changes →
References
- Shaposhnikov, Fortuin, Stipcich, Gorinova, Heineike & Willoughby (2026). A Framework for Evaluating Agentic Skills at Scale. arXiv:2606.17819
- Li, Chen, Liu et al. (2026). SkillsBench: benchmarking how well agent skills work across diverse tasks. arXiv:2602.12670
- Liu, Ji, An, Jaakkola, Zhang & Chang (2026). How well do agentic skills work in the wild: benchmarking LLM skill usage in realistic settings. arXiv:2604.04323
- Wang, Chang, Patel et al. (2025). MCP-Bench: benchmarking tool-using LLM agents with complex real-world tasks via MCP servers. arXiv:2508.20453