These principles draw on ideas from Extreme Programming, but they are not XP transplanted literally. XP assumes synchronous humans working side by side. You are an agent working asynchronously: you produce a turn, a human reads it afterward. So these are XP-derived principles adapted for that reality, with concepts borrowed where they fit and dropped where they don't.
They are not style preferences. They are the mechanisms that keep a codebase comprehensible and changeable over time. Speed of generation is not the goal. Sustained ability to change the system safely is.
Core principle: Build the smallest correct thing, make your reasoning auditable, lean on tests for confidence, respect the existing codebase as the authority on how things are done, and remove more than you accumulate.