Optimize data for large datasets

**Problem**
When working with core, 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 specific error path is named in the issue. Start by locating the core error-handling entry points in this Shell-based terminal agent and clarify which errors need improved messages; done should include agreed message details and coverage for the affected cases.

Written by the indexing model from the issue text.