You gain proficiency with Calligrapher's Tools, used to scribe scrolls. If you already have Calligrapher's Tools, you can pick a different tool. 

You can cast any spell scroll without making a skill check, regardless of spell level or which class list the spell is from. 

You use your spellcasting ability, spell attack bonus, and spellcasting save DC for all spell scrolls instead of only scrolls from your class spell list.

You can copy a scroll using Calligrapher's Tools. To do so, you follow usual scroll scribing rules, but you don't need to be able to cast the spell.