From the History tab you can see a list of changes that includes who made the change and when the change occurred.
Team Services: To work with a change, select it, click ..., and then click Compare Difference or Revert Definition.
Team Foundation Server (TFS) 2017 Update 1 and older: After you've viewed the history, if you want details about a change, select it and then choose Diff. If you want to roll back to an earlier version, select it, and then click Rollback.
Can I edit the JSON source directly?
Do I need an agent?
You need at least one agent to run your build or release. Get an agent.
I can't select a default agent queue and I can't queue my build or release. How do I fix this?