Optimize handlers for large datasets

**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 names no files, tests, or entry points. Start by locating the handlers and type-related error paths, then determine the intended scope from the surrounding implementation; done means the relevant errors provide more descriptive diagnostic messages and the existing checks still pass.

Written by the indexing model from the issue text.