I used to wear cargo shorts for women and this all fit in it except for the poncho:
Money
ID, insurance card, if I drive
AAA card and car insurance card
2 credit cards (used to only bring one but I once had my husband cancel one on me because of fraudulent charges and he forgot to tell me!)
advil
Rolaids and one immodium pill
Blister block for when I go to Epcot only - to use on my feet halfway through World Showcase
Sunscreen (travel size for refreshing on my face, hair part, ears and anywhere else I could reach)
extra camera batteries and SD card
my Small Canon camera SX260 HS - love this little camera
Cell phone (it goes into a Mophie case in the parks so the charge lasts all day)
Lip Balm
index card with my ADR's and FP+ written on it for each park (I only bring what will apply to the park I'm going to)
Oil Blotters for my face
Now that womens cargo shorts barely have usable pockets I've been carrying either a small purse or small backpack. I've also added a hand fan that I bought in Japan in Epcot to the bag. And a small travel comb and a scarf to cover my head if I feel like I'm getting a sunburn on my head (I hate hats).