Not sure which model or API key to use?

People rarely use one word for one thing. In a meeting the same form might be called “the intake form”, “the request” and “the service request”, and one word can mean two different things in two departments. Left alone, each story would pick its own wording and your diagrams would drift apart. Klarik reads the whole meeting once, settles on one name for each person, system and item, and remembers the other names people used for it. Every story is then written with those names.