I think I'll land on:

{:tasks {:clean [:shell {:description "foo"} "rm -rf target"]}}

thanks :)

Just curious if you are using Malli to make the DSL ?

not really no

although malli would probably be a good fit for validation

Landed on this one:

{:tasks {:clean {:description "Foo" :task [:shell "rm -rf target"]}}}

Not hiccup as usual, but I think the cleanest so far

@borkdude looks good, I would have suggested a map too, keeps the concepts separated.

Malli also has the generic map-syntax and have explored a third, simpler (clj-fx-like) map-syntax.

Need to pick a "better" map-syntax for malli 1.0.0, but will be first-class support, in malli.core. One can't mix syntaxes (terse/hiccup and map) freely, just one allowed per AST fragment.

@ikitommi what is clj-fx-like map syntax? would love to see it