Tags become confusing if they lack a description (usage guidance). So what should the well-meaning person do who wants to give those tags a description?
In the case of rationalism, it seems that the more educated users understand rationalism à la Descartes and not à la Yudkowsky or something like an standpoint that values reason and is opposed to superstition, etc. Does this justify a corresponding tag description?
In the case of libertarianism: users apply this to the political philosophy and to the free-will position. What should it be? That's nearly 50:50!