Imagine a support assistant built into a product that's been carefully localised. A customer in São Paulo opens it from a screen that's entirely in Brazilian Portuguese and asks where her order is. The assistant looks the order up with a tool call, reads back a block of English JSON, and replies: "Your order shipped on 11/04/2026 and should arrive by Thursday."
Every button around that reply is translated. The reply itself is in English, and the date in it reads as 11 April to anyone in Brazil, when the model meant 4 November.
Nobody wrote that sentence, so no translator ever saw it. A translation file can't hold text that doesn't exist until the model writes it. Chapters 8 and 9 covered using AI to translate your strings and your users' content. This chapter is about the AI features themselves: assistants, summaries, search and anything else in your product where a model writes text the user reads.