Study: AI agent 'skills' help via structure, not knowledge, and don't scale well

Researchers from Princeton and UC San Diego found that giving AI agents packaged "skills" improves performance mainly by providing structured workflows, not by adding new knowledge. As a skill library grows larger, agents increasingly struggle to find and select the right skill for a given task.

Why it matters: This complicates the fast-growing "agent skills" ecosystem by locating the real bottleneck in retrieval and selection rather than skill content itself, meaning bigger skill libraries can hurt as much as help. It reinforces a theme surfacing elsewhere this week: agent harness and workflow design increasingly matter more than raw model capability.