Definition is not always a benefit, it stops you from being something you’re not defined to be.
Doing work you’re proud of doesn’t require definition.
Doing work you’re proud of demonstrates what you’re good at, rather than what you ‘should’ be doing.
If you believe something is right, do it, whether it’s part of your job title/agency vision/remit, or not.
People will define you, in their own minds, based upon your work, not your mission statement.