The balance for a designer on how much information is given in a setting is a tricky one, and very much a matter of personal taste. Some GMs prefer the Designer to nail down every detail and hand them a finished box, where all they have to do is wind it up and stick in the PCs. Others feel hemmed in by too much supplied detail, and prefer a broader brush. Most, of course, fall somewhere in between. I have written both types of setting, but more and more as I get older, I prefer the latter. It's pushing stuff down to the group level, which is one of my most central beliefs - which those of you who read this blog regularly know very well. :D
Giving detail tends to focus games where the detail is densest, thus the Designer can - even unwittingly - push exploration down certain avenues. Personally. I'm much more interested in the group deciding that direction, not me. I don't *want* to channel play in a certain direction.
Now StarCluster 3 was far less Designer coersive than, say, Outremer will be, but SC3 went about as far as one can go in that direction. It was all about giving GMs the tools to create rather than doing the creation for the GM. Outremer is more about the setting itself - so I have to supply more detail. This means establishing some kind of cannon for the GM to work within.
Yet I find myself being asked by the playtest GMs for more information. I'm trying to work a subtle line here, where I only give information as it applies to macro structure - painting with a broad brush. Thing is, we are talking here not about worlds and star systems, but about tiny city states. This info-structure must be by its very nature finer-grained than what I am comfortable doing. My broad brush is much narrower here, and I am constantly finding myself putting in more details than I am comfortable doing - like the Cultural Traits of the various nations of Outremer. I keep thinking I should not have done that, that I should have let the GMs do that.
So I am calling a halt where I am in Outremer. There are a few things that have been suggested that I will implement - like the common-phrase language appendix, which will give a bit of flavor to those interested in doing so. OTOH, I will not give descriptions of important NPCs. That would be a huge temptation - it's fun to generate plot hooks, but that's not a Designer level thing, its a Group/GM level thing. It's a temptation that would sharply focus play in a direction I want. I gave the groups NPC generation tools so they can do this, now I will step out of the way and let them do it.