Reinforce critical rules at the point of use

A rule stated once in a long system prompt competes with everything else for the model's attention. For the rules that matter most, repeat them where the relevant action happens: in the tool description, and inside the tool's result. "Read before you answer" belongs in the system prompt and the read tool's description and as a reminder prepended to document content. Redundant reinforcement at the decision point measurably improves compliance.