Update helpers documentation

**Problem**
When working with routes, 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 name any files, tests, or entry points. Start by locating the route helpers and their current error handling, then determine which documentation and messages need updating; done means route failures provide more descriptive errors and the helpers documentation reflects the behavior.

Written by the indexing model from the issue text.