Consider deprecating old models API

**Problem**
When working with components, 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 old models API and the component error-handling paths in the Operator repository, then clarify which API is being deprecated and which messages need improvement. Done means the scope, deprecation behavior, and expected error details are agreed and covered by appropriate validation.

Written by the indexing model from the issue text.