We as testers need propper communication and procedures with developers

We (a 4 person QA-team) get our testing issues from an issue tracker. There our developers describe in a technical manner that a certain issue is somehow needed, how they implement it and at the end the write how we should test the new feature.

We do not use a certain process like Waterfall or Scrum and we do not have any specs to test against.

Right now we have some features that depend on other that are not yet completely implemented.

So sometimes we just do not know how features should work exactly, what has been implemented finally and what not and we find it kind of awkward that the developers tell us how we can test the features...

Are there best practices. Which should we go for first?

We as testers have the impression that it would be a big step to have specs for the features. How do we get there if time is costly?

Thanks a lot Marc