This said I was considering embedding it in the plugin GROUP to force to define a group of users capable of viewing the tool. This could be a mandatory option for the plugin to work, with a check that mobody adds the group "anonymous".
Another option might be to recycle an already existing permission, like tiki_p_list_trackers, to attribute to registered users.
But if it is not a problem, creating a new R category of permissions might be great. Other than that I can't figure out where to put this new permission.
I guess Jyhem will have the last word about the best option