I recently had a similar interpretation question and found these toy examples in R useful:

> aricode::ARI(c(1,1,2,2), c(1,1,2,2))
[1] 1
> aricode::ARI(c(1,1,2,2), c(2,2,1,1))
[1] 1
> aricode::ARI(c(1,1,2,2), c(1,2,1,2))
[1] -0.5
> aricode::ARI(c(1,1,2,1), c(1,2,1,2))
[1] 0