Refactor data for better readability

**Problem**
When working with types, 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 type-handling and error-reporting paths, then review how current errors are constructed. Done means the relevant errors provide more descriptive debugging context and the existing behavior remains covered or verifiable.

Written by the indexing model from the issue text.