Criteria for a Scrum Tool - or any Agile tool, that is

In one of the many mailing list threads on tools for Scrum teams, I posted a list of evaluation criteria that I'm quite happy with. So I decided that it might be worth a blog entry. Anyway, here they are:
In my view, there is one universal evaluation criterion for any Agile tool:

• does it provide what the team needs, in the simplest possible way?

To support self-organization, I'd probably add:

• did the team itself choose the tool?

From personal experience in small, colocated teams, I'd add a whole number of additional criteria for that context (in no particular order):

• is it highly flexible? Can it easily be adjusted as the needs of the team change over the course of a project?
• is it intuitive to use? Can I use it without having to think about it? Does it feel natural?
• is it highly visible? Can I see the current data without any effort, at a glance? Even by just passing by, or by looking up from my screen for a moment?
• is it highly collaborative? Can several people stand together and discuss with each other, with everyone having the same chance to work on the tool, and see and influence what everyone else is doing; concurrently on arbitrary different parts of the data? Do people notice when I look at it? Does the tool help start necessary conversations?
• does it provide easy navigation between high level and detail views? Is it possible to get a feel for the state of the Sprint at a glance? Is it easy to spot anomalities, and to dive into details?

The most appropriate tools I know for those requirements (again, remember that this is for a small, colocated team) still are cards on a wall and manually updated graphs on flip chart paper.

You Might Need To Leave Your Comfort Zone...

Some time ago, I facilitated an interesting workshop for my team, regarding communication when there is conflict. I presented a very simple model, where the communication was put on a scale from artificial harmony, over constructive conflict, to open war. (If I remember correctly, I got this model from the book "The Five Dysfunctions of a Team".)
An interesting discussion ensued, including on whether the scale really represented a true dimension of communication, what other dimensions there are etc.
The most interesting insight to me, though, unfolded towards the end, when it became clear that most of us were working under a common assumption: That people who feel comfortable with the more open, "hostile" communication styles must do so because of greater self-confidence. The implication being that it should be their responsibility to consider the needs of those with less self-confidence, by calming down their communication style.
When this assumption finally cropped up, one of our team-mates, often berated for her communication style at that time, commented that the assumption actually didn't hold true. She didn't feel more self-confident - in fact, she felt threatened by less open, more cautious communication styles. She felt threatened by not being able to truely understand her relationship to teammates, by conflicts potentially simmering under the surface instead of being carried out in the open.
The whole team was quite puzzled once I started drawing the implication on the white board - if two people are in conflict, they really might have comfort zones that don't overlap on the above mentioned scale. No matter what they do, at least one of them will feel uncomfortable.
What do you do in such a situation? My, somewhat lame, response was that you just accept that fact and learn to live with it. If you want to have that conflict resolved, you might need to leave your comfort zone. I guess that a coach or facilitator also can do things to help someone leave his comfort zone, or to widen comfort zones.
What would you do?