Document chunks should preserve the evidence people need to answer a real question, rather than obey one supposedly universal size. A rule can change meaning when retrieval drops its heading, warning, table, or exception from the surrounding document. Choose a small set of different boundaries and compare them using the same documents and difficult business questions. Place the original evidence beside the retrieved chunks. Inspect broken context before judging the fluency of the generated answer. Version boundary changes with their citations and rerun retrieval tests. A complete evidence unit matters more than an attractive token-count setting. Original article explainer. AI-assisted conceptual illustration and neural narration; original synthesized music. Not a human recording or customer result.