Although no "essential gear" is required during summertime, I recommend hikers taking this route to have:
1) At least one trekking pole or hiking stick. One is enough. It will help with balance & stability when climbing the steep scree and ash slopes.
2) Mountaineering boots or hiking boots. There are a lot of rocky areas where these would be preferred over sneakers, for sure.
Otherwise, good SP page. I studied the information when climbing the mountain this morning.
I would consider this route tougher than just a walk-up. A good portion of the route is scrambling over boulders, and hands are required in several places. Maybe there is a perfect clear route through the boulder field but I couldn't find it.