Improve middleware performance

**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.

No files, tests, or entry points are named. Start by locating the middleware implementation and its error-handling paths, then determine how performance and error-message detail should be evaluated; done means the intended middleware improvements are implemented and verified.

Written by the indexing model from the issue text.