Optimize lib for large datasets

**Problem**
When working with helpers, 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 helper implementations and their existing error-handling paths, then clarify which large-dataset behavior and messages are required. Done means the scope is agreed, errors provide actionable detail, and relevant checks cover the updated behavior.

Written by the indexing model from the issue text.