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Agents · Retrieval · Evaluation

Agent Skills in the Wild

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First page
Agent Skills in the Wild
The curator’s take

Agent skills look great in demos. Hand them a curated toolbox, and they shine. But what happens when the agent has to find the right skill from a library of 34,000? This paper from UC Santa Barbara and MIT presents the first comprehensive study of skill utility under progressively realistic settings, revealing that the benefits of skills are far more fragile than current evaluations suggest.

Key points
01

Progressive difficulty framework: The study moves from idealized conditions with hand-crafted, task-specific skills to realistic scenarios requiring retrieval from 34K real-world skills. Performance gains degrade consistently at each step, with pass rates approaching no-skill baselines in the most challenging scenarios.

02

Retrieval as the bottleneck: The core failure mode is not skill execution but skill selection. When agents must identify the right skill from a massive library, the retrieval step introduces errors that cascade through execution, highlighting a fundamental gap between demo-ready and production-ready skill systems.

03

Refinement strategies help but do not solve: Query-specific and query-agnostic refinement approaches show improvement, with Claude Opus 4.6 going from 57.7% to 65.5% on Terminal-Bench 2.0. However, even with refinement, performance under realistic retrieval conditions remains well below idealized baselines.

04

Implications for skill ecosystems: As the ecosystem of agent skills grows through frameworks like MCP, the findings suggest that simply expanding the skill library creates diminishing returns without corresponding advances in skill discovery. Quality of skill retrieval may matter more than quantity of available skills.

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