Yes — there's an effective limit, and it's shorter than you think. Past ~15-20 precise words, each additional word dilutes the ones before it. A 60-word style prompt doesn't give you more control; it gives you less.
1. The 10-word rule. Your best generations will come from ~10 strong words: smoky jazz trio, upright bass, brushed drums, late night, intimate. Every word earns its place.
2. Priority order: genre → instruments → mood → era. Put the most important thing first. If the singer matters most, lead with the singer. Front-load; back words get dropped first.
3. One idea per clause. Upbeat and melancholic in the same prompt cancel out. Pick a lane.
4. Move overflow to section brackets. Your style box is the global setting; put specifics where they belong: [Verse: fingerpicked acoustic], [Chorus: full band enters]. This is how you get detail WITHOUT a bloated style prompt.
5. If it's ignoring a specific instrument, it's usually not length — it's conflict. Check for a bigger, louder instrument crowding it out, and demote that one instead of shouting louder for yours.
Good luck! Hank founder of SonorixPG