What exactly the reviewers mean by saying "the contribution/novelty is limited"? I sometimes receive a comment from 1-2 of my reviewers saying something similar to "the contributions and novelty of the work/method is limited".
Consider it in the context of CS where you develop methods and algorithms which increase the performance of the state-of-the-art in a specific problem/domain.

Of course in every paper, i state my contributions for the reader to understand, but when i receive a general comment like that i get puzzled. Especially when there is no mutual communication between the author and the reviewer to clarify the misunderstandings.

So, let's say, in what typical situation a reviewer might vote for a critism like that?
Possibly related xkcd. Please don’t take offence!

I’ve seen some papers in CS which validly improve upon the state-of-the-art on particular datasets. In fact, you might find these where there is an ongoing annual challenge, or a specific dataset that is used. The numbers are good but they essentially glue two existing methods together. Sometimes there are perfectly novel contributions in the "glue": sticking these two methods together only works if you do it in a particular way, but "glue" contributions are smaller than completely novel "method" contributions and this might elicit such a response from a reviewer. Even if gluing these two methods together is novel.

Usually, in these papers, the results are great (they win the challenge/dataset) and I always wonder why the paper hasn’t been cited more. I think the answer to that is that the citations for the "method" contributions will go to the original papers and the "glue" contributions, if novel, might not transfer to other techniques or fields.