Review and improve this API design: [PASTE ENDPOINTS, REQUEST/RESPONSE SHAPES]. Evaluate: 1) RESTful resource naming conventions, 2) HTTP method and status code correctness, 3) Request/response schema consistency, 4) Pagination, filtering, and sorting patterns, 5) Error response format standardization, 6) Versioning strategy, 7) Authentication and authorization surface area, 8) Breaking change risks for existing clients. Provide a revised API spec with changes explained. Flag any endpoints that need breaking changes vs. backwards-compatible improvements.