Commuter bike should carry:

• 2 spare tubes
• 3 tire levers
• frame pump
• multi-tool
• lock
• keys
• wallet
• lunch-sized tupperware container
• laptop computer
• water bottle
• banana
• change of clothes
• a loaf of baggette bread picked up on the way home

Other design requirements that every non-cyclist who designs a commuter bike misses:

• fenders. absolutely required.
• easy tube changes
• must fit 35mm studded tire