Update helpers documentation

**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.

No files, tests, or entry points are named. Start by locating the helpers documentation and the current helper error-handling code, then determine which messages need clarification. Done means the affected documentation and error messages clearly describe the relevant failures, with appropriate tests or examples updated if they exist.

Written by the indexing model from the issue text.