Testing ChatGPT-5 Against Purpose, Clarity, and Authenticity in Business Writing

ChatGPT-5 has been praised as OpenAI’s most “human-sounding” model yet, with sharper reasoning and smoother writing. But how well does it actually perform in business communication? In this article, I test ChatGPT-5 against Writing in Blue Ink’s PCA framework (purpose, clarity, and authenticity). The results reveal where AI can strengthen your writing, and where only the human touch can carry the message.