What this checks

An SPF record may cause at most ten DNS lookups when a receiver evaluates it. Go over and the record returns permerror, which means SPF contributes nothing at all — and most of that budget is usually spent inside records belonging to the services you send through, not inside your own.

So this expands the whole tree, prices every include: with everything beneath it, and names the term that spends the tenth lookup. Enter a domain above, or paste a record you are about to publish.