We are trying to understand what the scope is of task updates. It seems that sometimes when we make a change to a task (such as a custom field), it does not show up as an update. But when we change the assignee, it does show up as an update.
Could someone help us understand what are the items in Asana that would show up as an update to task? And which would not?
These are called “Task activity feed stories” or often just “Stories” and amount to an incomplete audit trail for a task. I’m not sure they are thoroughly documented as you request, but the best I know of is found in these two Asana Guide posts. I recommend you skim through each in full because a number of sections touch on your question:
Keep in mind that this audit trail is not complete. In particular, changes are batched so, for example, if you change a custom field value a couple of times in a minute, only the final change will be reflected, not the interim ones.