How do I make zsh treat a variable with spaces as multiple arguments to a command?

Question

In bash, one variable can act as multiple arguments:

bash-3.2$ debug() {
>   echo num args: $#
> }
bash-3.2$ args="1 2 3"
bash-3.2$ debug $args
num args: 3
bash-3.2$ exit

In zsh, this same code treats $args as a single variable:

➜ debug() {
    echo num args: $#
  }
➜ args="1 2 3"
➜ debug $args
num args: 1

How do I make zsh treat a variable as multiple args the way that bash does?