A persistent issue I have with Cursor et al. is that they hallucinate function arguments when using a function or method from a library. It seems like automatically pulling the library's documentation into the context would be helpful, but I haven't found any tool that does this automatically. Is there any chance that Runner does this?

It doesn't seem like this was the problem you were trying to solve, but reliable use of libraries and APIs is a critical problem to solve if you want LLM-generated code to work.