Improve error messages in parsers

**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.

Start by locating the route parsers and their current error-handling entry points. Trace how malformed or invalid routes produce errors, then define and add more descriptive messages and verify the affected parser paths manually or with any existing tests.

Written by the indexing model from the issue text.