fix: add length check for toolRequestParts in `fromOpenAiChoice`

[pedi]

This pull request is related to:

• [x] A bug
• [ ] A new feature
• [ ] Documentation
• [ ] Other (please specify)

I have checked the following:

• [x] I have read and understood the contribution guidelines and the code of conduct;
• [x] I have added new tests (for bug fixes/features);
• [x] I have added/updated the documentation (for bug fixes / features).

Description: Please check description in the original issue

Related issues: Fix #137