The prefix is crucial. Many jazz collections offer “highlights” or “top 100” lists. The “FULL” version of the 557 standards claims to be exhaustive. It attempts to include not just the obvious Miles Davis and Charlie Parker classics, but also obscure B-sides from Broadway musicals, forgotten Tin Pan Alley gems, and modal explorations from the 1960s.
Many horn players jump straight to the chord changes to improvise. The 557 gives you the melody for a reason: transcribe it, ornament it, make it sing. The greatest improvisers always start with the head.
Don’t bring the book to the gig. The goal is to internalize the 557 so you can close your eyes and play. Use the book for reference, but memorize four tunes a week.