I think it’s an interesting idea to try to name the unsafe blocks but my solution is not focused on them. They are part of the solution but not in the center. I simply want a quick (and automatic) way to describe what a crate is doing at the high level. If it is not using any library (nothing from std) and not using unsafe blocks then I am sure that it will not steal my data or put evil stuff on my disk. If it is using std::fs:: or std::net then I am a little more sceptical. If it is using unsafe and calling c functions then all bets are off. I really need to check the code in that case (or delegate the audit to someone else).
By the way, we also need a method to somehow decide whether a given unsafe block was changed. If I checked version 1.2 and found it safe and this automatic checker is not complaining about new unsafe blocks that doesn’t mean that the author did not put something evil in the already existing unsafe blocks.