Groups of words that are not usually adjectives but function together as an adjective before a noun are hyphenated. Such groups of words count as one word.

Examples in STE:

Use the trial-and-error method. (4 words)

When you hyphenate long technical names to make them clearer to the reader, a hyphenated group of words also counts as one word in the applicable noun cluster.

Main-gear-door retraction-winch handle (3 words)