You can do this, but it's a bit fragile
foo.sh will look like this
#! /bin/bash declare "$@" # evaluate the params as variable declarations bar $bar_args # not quoted! baz $baz_args # not quoted!
Then, ./foo.sh bar_args="-x -v message=hello" baz_args="-d -m"
will work like you hope.
Do not attempt to pass a message with whitespace in it, can't be done in this manner.