Optimize validation 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.

No file, test, or entry point is named. First locate the validation path for types and large datasets, then identify the existing error-handling tests or add a focused test; done means the relevant failures produce detailed, useful messages and the validation behavior is covered.

Written by the indexing model from the issue text.