Update models documentation

**Problem**
When working with utils, 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 models documentation and utils but does not identify a file, test, or entry point. First locate the models documentation and the utils error-handling code, then clarify which messages should change and how the improved behavior will be verified.

Written by the indexing model from the issue text.