Build in Content Pipeline Tool

Hi everyone!
I’m starting to make sense of Monogame structure and after doing some experiments I was wondering about something.
When I add a new item in the Content Pipeline Tool (a sprite), if I just save without building, when I build the solution, everything is working fine. So I assume that the building of the content resources is done even if I don’t do it manually.
Some people say we must always build the content resources inside the Content Pipeline Tool.
So here is my question:
Is building inside the Content Pipeline mandatory or a recommandation for good practices or is it any useful?
Are there some caveat not building?
Is there a reason to do it manually?
Thanks in advance.

If you look inside your solution (assuming Visual Studio), you’ll see that the Content.mgcb file is included with a Build Action of MonoGameContentReference. Whenever you hit run, it will build that Content file first then run your game if there are no errors. It is actually building your content with the pipeline tool, but it is doing so automatically from Visual Studio for convenience.

Thank you. Now I understand why it works.