Handle edge cases in pagination

**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.

The issue does not name any files, tests, or entry points. Start by locating route pagination and error-handling code, then reproduce the pagination edge cases described by the title; done means the affected cases produce detailed, useful error messages and the relevant tests pass.

Written by the indexing model from the issue text.