Update utils 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.

Start by locating the utils documentation and the related error-handling entry points in the repository. Determine which error cases need more descriptive messages and which documentation pages describe them. The work is done when the affected messages and documentation are updated consistently and the relevant existing checks pass.

Written by the indexing model from the issue text.