Refactor utils 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.

The issue does not name files, tests, or an entry point. Start by locating the utils code and the paths that handle types and produce errors, then read the existing tests around those paths. Done means the relevant type errors are more descriptive without changing their intended behavior, with coverage for the revised messages.

Written by the indexing model from the issue text.