Can't do it out of box.
Well, officially. Unofficially, you can write javascript into field description in field configuration (and that field configuration must be only used by that 1 specific project so as not to call that javascript anywhere else) which would populate the textarea, but it's a b**** and a half to maintain javascripts that way.
Atlassian actually have a KBA how to do exactly this for Summary - https://confluence.atlassian.com/jirakb/how-to-set-default-value-for-summary-field-in-jira-800692650.html ; Description will be essentially the same.
Officially, you would need 3rd party apps. The one we use for similar purposes is ScriptRunner (https://marketplace.atlassian.com/apps/6820/scriptrunner-for-jira?hosting=datacenter&tab=overview) which has behaviours that allow to customize the default text for system fields:
# https://docs.adaptavist.com/sr4js/latest/features/behaviours
I'm sure there are some other apps that do it (and they probably work w/ javascript anyway, but at least it's easier to maintain it through custom plugin UI). ScriptRunner is packed with a ton of other features so unless you already have it, best to look for something else as SR would be pricy if this was the only use case for it. Can't say I can think of an app from the top of my head though as we use behaviours for this in all cases pretty much.
You must be a registered user to add a comment. If you've already registered, sign in. Otherwise, register and sign in.