Using the future "werden" with Alles or Alle ?

[schaffel1949]

In comparing these two sentences:

Alle werden ins Restaurant gehen.

and

Alles wird gut schmecken.

Why is the werden form different ?

What clue in each sentence would let me know what person form of werden to use?

[Sprachprofi]

alle = all [people]. It's plural, hence the -e ending and the verb is plural.
alles = everything. It's neuter singular, hence the -s ending and the verb is singular.