Improve routes performance

**Problem**
When working with validation, 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 searching the repository for route handling, validation, and error-generation code, then trace how validation failures are reported. Done means the relevant validation errors provide more descriptive debugging context and the existing behavior remains covered by tests.

Written by the indexing model from the issue text.