# The Three-Layer Problem: Why AI Agents Learn Differently Than Models

- slug: the-three-layer-problem-why-ai-agents-learn-differently-than-models
- date: 2026-04-05
- category: Agentics

Harrison Chase just redrew the map of AI agent development. The model layer gets all the press, but the real action is in the harness and context layers — and a new paper from Stanford and Google puts hard numbers behind why.

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