Honesty in a language model encompasses several related properties: being truthful (not stating things it believes to be false), being calibrated (not expressing more confidence than warranted), being transparent (not pursuing hidden agendas or deceiving users about its nature), and being non-manipulative (relying on legitimate means like reasoning and evidence rather than exploiting psychological weaknesses). Honesty is harder to enforce than it sounds — models can create false impressions through technically true but misleading statements, selective emphasis, or confident phrasing that implies certainty they don’t have. For behavior architects, building honest behavior means going beyond “don’t lie” to address the full range of ways a model can mislead users.