Improve error messages in auth

**Problem**
When working with helpers, 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 helpers and tracing their current error paths. Review how failures are reported, then define the expected descriptive messages and verify that the relevant authentication failures expose enough context for debugging.

Written by the indexing model from the issue text.