Improve error messages in models

**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.

No file, test, or entry point is named. Start by tracing model and component error-handling paths in the repository, then identify which failures currently lack useful context. Done means the affected errors have agreed descriptive messages and coverage for the changed cases.

Written by the indexing model from the issue text.