In my tool bag:
- Multitool
- a couple of standard size Allen keys
- Chain tool
- Spare quick links
- Quick link tool (makes opening and closing quick links easy)
- steel tire levers
- needle nose pliers
- patches
- rubber cement
Additionally, I also carry a spare tube and a mini-pump attached to the frame. The only time I don't carry tools / pump is when I'm riding close to home and could easily walk home in the event of mechanical issues.