Assess how easy this copy is to read and skim on a phone, mid-scroll, by someone giving it about half a second before deciding whether to keep reading.
The rest of the Tier 1 toolkit, as it ships, straight to your inbox.
Also worth a look: the Product Page Grader
One calculator rarely tells the whole story. This is the order that actually works: from margin, to target, to a page that can convert the traffic you send it.