Refactor middleware for better readability

**Problem**
When working with hooks, 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 or tests are named. Start by locating the middleware and hook error-handling entry points, then read the existing error messages and their callers. Done means the middleware is easier to follow and hook failures provide more descriptive messages, with relevant existing checks still passing.

Written by the indexing model from the issue text.