I work in a smaller agency structure taking on projects from somewhat large informational projects to startup web apps.
When passing work to a visual designer, I pass the following (which they may or may not look at)
- User Flow diagrams
- Content Map (adapted from OOUX)
- Low to mid-fidelity wireframes (maybe clickable using UX Pin)
Low to mid-fidelity wireframes
I've come to expect them to use this the most, and I try to make sure that important information is distilled from materials above, into whatever their particular task-at-hand is. But it helps to have the additional reference material above for discussion and higher-level understanding. Sometimes the additional material come up when I include additional notes within wireframes when it seems appropriate, either in the form of:
1. general page notes: page objectives [first, second, third, ...];
2. or specific annotations: let's make sure this (X) is prioritized visually (might lead to short discussion), or this (Y) is flexible and we can consider whichever way you'd like to try it (I may or may not know what they're interested in working on but want them to find fulfilment, incorporate ideas, and test their ideas against the objectives to improve both our understanding of this whole thing, etc)
I'm not sure what kinds of things you're building and what the most important aspects are, but it seems like this: the things you are really accountable for are the things you either want buy-in from the people above you, or the people around you. If from 'above you' then those are the things you want to be certain about (in general notes as directions, annotations, or discussion), if from 'around you' then those general notes as discussion points, and knowing who your designers are will help.
About my role - thought on UX and knowing your team
I have noticed that each designer uses these wireframes differently. One will often use it as a general direction and the other will follow it very strictly. Which is to say, my role in UX isn't that flexible (i almost always produce the same materials in one way or another), but the fact that I am managing the output, working with very different kinds of people, and so on, means that I am more flexible as a person.
Questions for you
1. I realize I am waaay late on this. How did it go?
2. What kinds of things did you add to this list?
3. Did I address your point at all?