The problem is really more getting the agent to reliable relay a UUID. For example, we were creating files for visualizations and having the agent reference them in there response with a custom <visualization file=UUID /> and found that it would often fail to accurately return a UUID from a tool response it was previously provided (running sonnet 4.6).

For this use case, our solution was just to use a slug for the filename, but we can control the uniqueness constraint on our backend.