A SaaS customer messages support on a Tuesday morning. They've lost three days of data. Their brand voice document — the one the marketing team wrote two years ago — says the brand is "friendly, approachable, and helpful." The support engineer drafts a reply. It's friendly.

Most brand voice documents are useless within ninety days. They sit in a Notion page nobody opens, made of adjectives that can't be falsified — friendly, professional, expert, approachable, human. Six months later the marketing team has turned over, three freelancers have written copy under the brief, and the