A well-designed API should prioritize the developer experience by providing clear documentation, easy authentication and authorization processes, standardized protocols and styles, and a user-friendly interface. A good API should also be designed around common use cases, offer flexible pricing plans with transparent limits and costs, provide responsive support options, and include features such as versioning, data export, and a customer portal to help manage administrative tasks and ensure compliance with regulations. By considering these factors, developers can make informed decisions when choosing an API that meets their needs and supports the growth of their applications and businesses.