Help with predicates... again

Heeeyyyyyy... So I used misode to generate this json file for the predicate and it's just not working for some reason... I set up a command block to run particles at @a[predicate=is_sneaking] to test it, but nothing happens. The predicate file path is data/namespace/predicates/is_sneaking.json It doesn't seem to be registering the predicate at all. What am I doing wrong here?