I made simple Swift Macro here is article how to use it https://kment-robin.medium.com/codable-and-swiftdata-179418b2c460

I recreate the same issue I have with Apple Demo project Fruta repo is here: https://github.com/kmentrobin/Fruta-macOS-Widget

The problem was in .intentdefinition where is needed for macOS to have Checked value Siri can ask for value when run. Don't know why but that only helped. If you want to play around with that is still on GitHub.