Malic - if you want MLF (malolactic fermentation, a bacterial secondary process that gives that farmyard scrumpy flavour) you'll need it as the malic acid is what it works on, and there ain't much in commercial AJ. If you're not bothered about MLF there may be enough acid already, but a bit more won't hurt. If you're not doing MLF, the AJ may be a bit thin tasting on its own, add a bit of something else.
Tannin - Adds "bite". Your brew will be very boring without some. 1 tsp/gallon powdered or mug of stupidly strong tea per gallon.
Nutrient - The yeast needs feeding. AJ doesn't have everything it needs, so give it some of the commercial stuff. Yeh, you can use tom puree, maybe some crushed vitamin B1 tablets, but it's not as good as proper di-ammonium phosphate.