Improve services performance

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

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

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

Start by locating the authentication service and its current error-handling paths, then reproduce the existing errors to understand what context is missing. Improve the messages so authentication failures are more descriptive and verify that the relevant debugging scenarios are clearer without changing the intended behavior.

Written by the indexing model from the issue text.