Andrew Vos tweeted (@AndrewVos, 15 Nov 2012):
Hey, guys! Guys. Listen. I found this new agile tool! It’s called “writing stuff down in a list, then doing them one by one”1
Andrew is right, the core of Agile planning is a list. Actually several lists. The product backlog is just a list of high level requirements. A sprint backlog is just a list of tasks to do during the sprint. And, more or less, the team does them one by one from the top priority to lowest priority.
But I disagree with the colleague of mine who said to me a couple of years back “Agile is just managing lists.”
The lists are useful tools for our own time management or for managing a team. But there is a lot more to Agile than just managing lists including: 
- Acknowledging it is all about people
 - Product ownership
 - Technical practices including automated testing
 - Focus on communication, e.g. colocation, daily stand ups
 - Making things visible, e.g. boards
 - Flexible scope
 - Delegation to the lowest responsible level
 - Deferring decisions to the last responsible moment e.g. Pain Driven Development
 - Emphasising user needs in requirements rather than technical components
 - etc, etc
 
Notes
(1) I moderated Andrew’s language somewhat.