[gabrielsroka]

this seems to work almost as well (except for error handling, etc)

  javascript:navigator.clipboard.readText().then(t => open().document.write(t))

also, when writing a bookmarklet, you can add /* block comments */ and still copy/paste or drag/drop, eg:

  javascript:/* show the sum */alert(2+2)

but // comments don't work

  javascript://this won't work;alert(2+2)