Add rate limiting for backup

**Problem**
When working with handlers, the error messages could be more descriptive.

**Suggestion**
Improve error handling and add detailed error messages.

**Context**
This would help with debugging and maintenance.

The issue names no files, tests, or handler entry point, and its body does not explain how backup rate limiting should work. First locate the backup and handler code, then clarify the intended limit and error-message behavior; done should include the requested limiting and descriptive errors with tests demonstrating both.

Written by the indexing model from the issue text.