The S in S&F stands for Script. Teaching requires active engagement, not passive thought; the basis of our planning therefor needs to reflect this. It is not enough to consider weighty ideas, you need to think about how you are going to put them into action, and what your students are going to do, and what you are going to talk about, and what is going to happen. Therefore for your script you need to think in very physical, active terms. Verbs, not adverbs or adjectives. Actions, not concepts.
In one respect only this 'script' does not mirror an actor's script: you do not (or need not) write down word-for-word what you are going to say - only a clear concise summary. . Apart from that, the Script should offer the equivalent of stage directions for each episode in the lesson. In how much detail? In exactly as much detail as you yourself need, dear reader. This is real planning, with a real purpose: we plan until we have removed uncertainty and discontinuity from our plans; as long as it is clear to you what you are going to do and when, that's fine.