The phrase "avoid gratuitous" is correct and usable in written English.
It can be used when advising someone to refrain from unnecessary or excessive actions, often in the context of writing or speech.
Example: "In your essay, make sure to avoid gratuitous details that do not contribute to your main argument."
Alternatives: "steer clear of unnecessary" or "refrain from excessive".
The Times's efforts to avoid gratuitous vulgarity have sometimes produced difficult distinctions.
There was a duty to survive, to keep things running, to avoid gratuitous provocation that might make a bad case worse.
Our leaders should avoid gratuitous insults to the Russians, but it is wrong to suggest that we need fear a renewed competition with them.
The designer, Danny Ledonne, had high ideas about it: he chose low-fi effects to avoid gratuitous gore and included actual dialogue from the teenagers to give insight into their troubled minds.
(Avoid gratuitous comparisons to Bears quarterback Jay Cutler because their situations are not at all comparable, other than suggesting Cutler could take a few lessons in public relations from the gracious Nadal).
I groaned when I heard Ben Affleck was going to be Batman, and I've avoided gratuitous slow-mo abuser Zack Snyder entirely.
The camera never obsesses over specifics, avoiding needless or gratuitous close-ups, but it also never shies away from what's taking place: hot and steamy gay sex.
We avoid the gratuitous revelation of secrets.
Minority officers may also see with greater clarity why so many communities feel so distant from police, why good people on each side of a human divide must reach out, and — at minimum — avoid inflicting gratuitous offense.
Circuses may be transgressing the Jewish edict of tzaar ba'alei chaim, the commandment to avoid inflicting gratuitous pain on animals.
He now avoids giving gratuitous offence and shields his mouth when whispering in people's ears.
