Update config documentation

**Problem**
When working with api, 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 configuration documentation and the API error-handling entry point. Review the current error messages and identify which configuration details are missing from them; done means the affected documentation and messages are more descriptive and consistent.

Written by the indexing model from the issue text.