PB Quality Grade

An A–F quality assessment of a Prompt Book that evaluates whether the prompts are well-formed, semantically diverse, and representative of genuine user intent for the given Focus. Grades are computed after PB generation and before measurement. Grades below B trigger automatic regeneration with revised generation parameters. Grade F is a hard block — VS measurement cannot proceed until the PB passes minimum quality thresholds. A high-grade PB is the prerequisite for VS results that are meaningful rather than artifactual.