Web Audio Tool is a wrapper around the graph creation/modification part of the Web Audio API, where you setup and connect
the nodes that you need for your application. Doing this by code can be quite confusing when you end up with a huge amount of code that doesn't give any overview at all about the network that you're building. That's where the editor comes in: you can cleary see what you are creating and what's connected with what.
get information about the current nodes and connections
easily remove single nodes or connections from the graph
inject (or remove) large subgraphs into the current one by a single command
TLDR: Web Audio Tool wants to make the creation of the audio network easy, after that you will still talk to the Web Audio API in the same way that you do now.
why should you use it?
visual editor to create your sound graph
save your creations as a patch
supports nested subpatches
why should you not use it?
this is currently a very, very early alpha release
no, really. i'm serious.
load patches directly in your code with a soon to be released library
library of effects, sequencers and sound generators, consisting of both subpatches (a nested patch) and custom nodes (through Audio Workers)
share patches, subpatches, custom nodes with other users
Last but not least, a shameless plug for my previous sound project: Patchwork Synth