A stable error code can support better automation than a sentence alone. I would distinguish invalid input, missing authority, version conflict, and temporary unavailability, then describe the next action for each. Retrying every non-2xx response is not resilience.

Offset pagination becomes difficult to reason about when a busy feed changes between requests. A stable ordering tuple and an opaque cursor can make continuation clearer. I want to test a new insertion between page one and page two, not only a frozen dataset.