The first time I noticed that particular technique in dialogue tags in Doris Lessing's
The Golden Notebook. I'm sure I've seen it before, and I've certainly seen it since. It's a common technique. Some people like to place attributes towards the nouns rather than the verbs. Some people (like the OP, here) like it for the rhythm.
Since
The Golden Notebook is available
here, I can give you a couple of examples:
‘Didn’t he write to you?’ asked Anna, cautious.
Pretty straightforward. Anna asked this and she was cautious. "asked Anna caustiously" would have been possible, too. I see a slight difference in emphasis, but nothing world-shatteringly important. It's a matter of preference.
‘He’ll probably go when he sees me here,’ said Anna, cheerfully, but slightly aggressive.
See how Lessing mixes adverb with adjective? She could have been consistent:
...said Anna, cheerfully, but slightly aggressively.
[Ugly rhythm.]
...said Anna, cheerful, but slightly aggressive.
[Possible. There may be a slight difference in emphasis; perhaps a level shift. By linking the attribute "cheerful" to the verb "say", but the attribute "aggressive" to the person, Anna, the "aggressive" might stand out more - as more geniune. Thus the "cheerfulness" could be read as a sort of mask.]
[Also notice that I left the commas intact. Grammar doesn't force them before a "but"; actually, in a list of two, the comma is unusual. This might heighten the sense of separation (in addition to the adverb/adjective distinction). I do think Lessing knew what she was doing here, though perhaps subconsciously - I'm afraid she'll hit me over the head with the book if she ever reads these lines, and
The Golden Notebook is heavy even in paperback format...)
‘You’ve only just understood that?’ said Molly, triumphant as always when Anna came up with — as far as she was concerned — facts that were self-evident.
Here the adjective, "triumphant", is actually better, since the omniscient narrator uses the adjective to lead into a fact about Anna.
***
I'll quit here. Your technique is perfectly fine, Sheherazade. People have used it before. Often. It's a pretty straightforward method. As I said, I'd call it a verbless clause, but that won't fly with people who like "traditional grammar", since in traditional grammar "verbless clause" is a contradiction in terms (as, in traditional grammar, a clause needs a subject and a verb). I'm not sure what a traditional grammarian would call that. Traditional grammar, based on Latin, is often not very good at describing the odds and ends at English, and people who like traditional grammar often mistake a flaw in their pet theories for a flaw in your usage. I'm sure traditional grammarians have tackled these structures as well, but I'm not sure what they would call them. [
Here's a little discussion on this phenomenon. One alternative term mentioned is "adverbial adjunct that modifies the main clause" - which I admit is an interesting possibility, but it's not traditional grammar, either.]
In the end, it doesn't matter what label you pin to the structures. They exist. They are common. You can use them if you like them.