In our short history as independent screenwriters slash independent producers, my partner and used to write character sketches after the script was finalized. We would make them available, rather than give them, to the director and the actors.
Some directors, the ones I label “Visual Directors” were not a bit interested in the sketches. To them it was all about camera angles, great framing, and good shot variation. Other directors, the “Emotional Directors,” would read the sketches, maybe using them for casting assistance or help working with the actors on set. Some Emotional Directors just read the sketches to give themselves more information; then they chose to formulate their own notions of the characters’ back-stories.
Some actors choose not to read the sketches, too. I was surprised by that. As an actor myself, I always write my own back story when I’m cast; I’ve never been given one by a director or writer. Seems to me I’d be glad to get a character sketch so I knew what was in the director’s head. But, maybe not. Maybe to own the character, the actor needs to create her own back-story.
Looking back at the times we have written these sketches, I think that perhaps we felt compelled to create character sketches because the script itself was not excellent enough to give the actor that information. Looking forward at the feature-length I’m writing, I doubt I’ll write character sketches post-script. My new writing partner likes to answer a series of questions about each character during the writing, but does not share any of this with anyone but her co-writers.