The Scaling Laws of Skills in LLM Agent Systems
This study analyzes 15 frontier LLMs, 1,141 real-world skills, and over 3 million routing/execution decisions, identifying two coupled scaling laws in LLM agent systems: the routing law (single-step routing accuracy decays logarithmically with library size) and the execution law (correct execution improves difficult downstream decisions by about 4×). A single parameter b couples the two laws. Law-guided optimization raises held-out routing accuracy from 71.3% to 91.7%, reduces hijack from 22.4% to 4.1%, and improves pass rates on downstream benchmarks. Results show agent performance depends not only on model capability but also on skill library structure, granularity, and exposure policy.