Add the 81st skill to your agent.
Retrieval starts missing. The router pulls a near-miss instead of the right primitive. The agent runs with shallow context, the task fails, and you debug the wrong layer.
That number isn't folklore. Reganti's SkillsBench measured it across 26,262 skills. The retrieval-collapse threshold sits around 80 flat skills. Past that point, accuracy degrades smoothly and silently. The router returns the second-best skill, the model uses it, and you attribute the failure to model quality.
2026 skill management has three load-bearing axes: classification, need-aware loading, composition.
Classification. Five empirical patterns: Tool Wrapper, Generator, Reviewer, Inversion, Pipeline. Each has different retrieval behavior. Tool Wrappers cluster tightly in embedding space. Mixing patterns without intent fragments the search index.