How API consumers are applying and integrating your API resources and capabilities will help you define where you invest across the API lifecycle. Knowing how your API consumers will integrate, automate, and orchestrate will shape which programming languages SDKs you invest in, which platforms and integrations matter the most.
The how portion of the use cases for an API is about the real world details of programming languages, existing infrastructure, services, and tooling used by consumers, and the other things that will help you dovetail your API experience with the needs of your consumers.
How an API is used will shape the design, the headers and transport patterns, media types, and other technical details. Having how APIs will be used will help you do more with less by prioritizing on what is needed, and not wasting time on what your consumers do not need or care about. Understanding how your API consumers are using your API is how you optimize the retail distribution of your digital resources and capabilities.