Update utils documentation

**Problem**
When working with handlers, 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 does not identify a file, test, or handler entry point. Start by locating the utils documentation and the handlers whose errors are described; done means the documentation and error messages are more descriptive, with the expected wording agreed and checked.

Written by the indexing model from the issue text.