In fact, I'm thinking these details would be pretty much the entire description: the build-a-spell system will focus on spell names that describe simple events and transformations, combined with a list of spell categories and the modifiers that apply, like so:
- Create Light (sensory) -- Level I dynamic non-combat, creation
- Explode Fireball (ranged damage) -- Level III combat, attack
The other simplification I'm thinking about is pruning the spell types (keywords) lists. I want to think purely in terms of limits: what spells a particular spell caster can't possibly do, and what spells they can only do after reaching a certain level. There's pretty much no need to list 1st level spell types at all, and some of the other types can be merged or generalized; for example, creation of matter and physical transformation seems to 4th level in general, otherworldly conjuration or communication is 5th, and large-scale physical changes are 6th level. So, all that needs to be noted are exceptions (magic-user can't cause instant death or cheat death (reincarnation spell) until 6th level.
I'll have to work on this some more to see if I can compress it further while making it more useful to the average gamer.