That's correct! We deprecated ToolOutput in beta 5, and replaced it with either String or GeneratedContent tool output. For more, see the Tool's doc: https://developer.apple.com/documentation/foundationmodels/tool

Howdy! When the model "get's stuck" the only work-around is to start a new LanguageModelSession. Generally "getting stuck" is a signal that the model is struggling with your request. I'm not surprised the model is struggling with this one. The on-device ~3B language model isn't a coding model, so while it does know a little bit about code, it hasn't been trained for most code tasks. In this case, the model is giving its best shot but can't quite solve the task. I'd recommend avoiding code tasks for this model.