Read-only feature:

Play as or receive bonus from this character, depending on the mode

amiibo with written game data from Mario Party 10 will carry over that data as special dice.

Even without Mario Party 10 data, Gold Mario will start with gold dice and Silver Mario will start with silver dice.

Source: / Thanks: memoryman3

Read-only feature:

Unlock "Chill" track in Rhythm Recital mode


Read-only feature:

See fireworks, shooting stars, balloons, or confetti in the hub world

This feature works with any amiibo (with the possible exception of those that work with its other features).

Source: Mario Wiki