You seem to be missing one important thing. There are tools with only one option, or even no settings at all, and other tools with a lot of settings. And it can be frequently switched tools in one editor and mode.
And if you place the tool settings horizontally, it doesn’t matter if it’s one common top bar or per editor header, then you will either have a lot of empty unused space, or lack of space.
Also in this case you will have two different layouts of the same settings, one horizontally panel and the other in Properties editor, which is bad for remembering.
As I suggested earlier, you can see the screenshots here, the straightforward solution is to use a vertical panel for the tool settings, with exactly the same content as in the Properties editor.
This can be on the right, along with the Sidebar, or on the left near the Tools. It can be full-height or small panel when there are few settings. It can be opened by double-clicking on the tool icon and automatically closes when losing focus, etc.
Also there will be no problem if you need to add more settings to the tool in the future.