Most of the "markers" I use in the shop have a "yes but" factor, pen or pencil there is something that is a PITA. I have found a mechanical pencil that while it doesn't address all the "yes buts" comes pretty damn close.
The Zebra Del Guard Mechanical Pencil with a 0.5mm lead is the best all around marker I've found. You can find them on Amazon.
The lead is thin enough to mark inside a knife line but because of the way it is supported will not break as easily as other 0.5mm pencil leads.
I just finished marking out a small box, I broke the lead three times which if you have used a 0.5mm mechanical pencil is pretty amazing.
BTW, the reason I'm marking out a small box is I'm finally getting around to making MsBubba's dining room table. My associated trip to the wood store was pretty disappointing. There were not a lot of 8/4 wood on the racks and what was there was pretty grim or over $8 USD a board foot. The exception was Alder both clear and knotty.
I've never worked with Alder so I bought a small 4/4 board to play with, to see how it works and takes finish. I thought "self, what better way to test wood than make something out of it". I haven't made a small box in awhile so might as well. Kinda a long way around to a mechanical pencil, working Alder, and making a table for MsBubba but that's life, it is almost never linear.
BTW, that is a piece of the Alder under the pencil.