Add rate limiting for import

**Problem**
When working with controllers, 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 controller import path and existing error handling, then clarify the rate-limiting policy and expected messages; done means imports are limited and failures provide detailed errors.

Written by the indexing model from the issue text.