Update utils documentation

**Problem**
When working with middleware, 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 utils documentation and middleware error messages but no files, tests, or entry points. Start by locating the relevant utils documentation and middleware error-handling paths; done means the documentation and error messages clearly describe the middleware failures and improve debugging.

Written by the indexing model from the issue text.