The pdf is ok, but if you can afford the extra value, I would rather invest in "The Solo Adventurer's Toolbox" even though it's a D&D material, I have got much more value, in both material and tables, which I find quite essential when playing solo. "Tome of Adventure Design" also brings much more value.

It brings some cool mechanics like the Drama Pool and the Event Dice, but I feel like it lacks material exclusive to DCC, like tips on how to use the monster tables provided by DCC to generate random monsters. (There are tables for Dragons, Demons, Undead traits and so on) Some tips on random encounters, I don't feel like the Icon Dice do the trick, as it leaves entirelly to your imagination, and as you are playing solo, you really need some quick monsters/traps, on the fly to avoid disruption of the game flow and your immersion.

When playing DCC solo I have had a blast using a mix of the "Four Against Darkness" for dungeon generation, using events and encounters(dungeon, wilderness and urban) from "The Solo Adventurer's Toolbox", using themes and tropes generated from "Tome of Adventure Design". I get random monsters on the fly from https://juliosrpgcove.com/monstergenerator/ such a good site, with many amazing tools! I can't help but promote it. As such I had extracted very little value from the purchase, but if you are just starting to dabble into "Solo Play" with DCC, I feel like the book will give you a decent start.