Drawer icon: I'm guessing that you feed output of tool drawer to cycle-tools input? Then when there's "no tool selected", it doesn't cycle because there's no signal. You could just add power (drawn from any source, like a NOT gate or battery terminal) to the input, instead.
Saw tool: Yes, saw acts on an item bumped whereas shovel & dibble act on bare ground.
Work around: You may not yet have enough automation to do saw-shovel-dibble in one go, yet. Later circuitry simplifies this but, for now, you might find it easier to do a saw/gather pass, a shovel pass then a dibble pass. Perhaps changing tools based on turning around at the rock-walls. Do you have sensors, yet?
During early-game, there's a bit of manual-labor required. Each phase of the game is intended to nudge you toward automating the thing that you're mostly doing manually now, and then getting you to spend your (human player) time doing some new thing. Then you solve that and it all shifts down one. That is, more or less, the game progression, until you get to the point where you push a single button and your team of robots does as instructed

In my early farm, I would tend to do plots of 4-8 rows (depending on my seed resources), saw them in a zig-zag fashion, then manually "drive" to start to hoe the same plot, then manual-drive to plant until out of seeds. Later, I added a counter so it would auto-stop after N rows. Later, I added the "...then return to the top of the loop" logic. I'm pretty sure all of that logic was locked-up in chips before I managed to have a "now do the whole thing, all at once" robot.
YMMV. Feel free to invent!
Circuit notes: Once you get to chips, they can be annotated with text. For non-chip circuits, the best thing we have currently is colored wire.
I'll add a feature request for user-supplied labels -- seems easy enough...