JoinFieldValue

I'm having problems with a JoinFieldValue statement.

When a new contact is created, my users want the phone number to default to the Account phone number.

So under the contact phone, I entered this as the default:

JoinFieldValue('<Account>',[<AccountId>],'<Phone>')

It doesn't pass syntax check.  I get an error that says "The definition of integration component field 'Phone' for integration component 'Account' in integration object 'Account_Occam' is invalid."

So what am I doing wrong?