I really like these 6 Rules by Chief Technology Officer (CTO) "Dr. Werner Vogel" of Amazon Web Services (AWS):
- APIs are Forever
- Never Break Backward Compatibility
- Work Backwards from Customer Use Cases
- Create APIs That are Self Describing and Have a Clear, Specific Purpose
- Create APIs with Explicit and Well-Documented Failure Modes
- Avoid Leaking Implementation Details at All Costs
For details, read this article - https://thenewstack.io/werner-vogels-6-rules-for-good-api-design/
Or, watch his video -