Not too sure if this is what you are after, it will create a text file on the desktop with the names of all loaded brushes.
[CODE]
#target Photoshop;
var f = new File(Folder.desktop + "/Brush List.txt");
f.open("w");
f.writeln(getBrushList().join("\n"));
f.close();
alert("File created \n" + decodeURI(f));
function getBrushList(){
var desc, brushList, ref;
ref = new ActionReference();
ref.putProperty( charIDToTypeID("Prpr"), stringIDToTypeID("presetManager") );
ref.putEnumerated( charIDToTypeID("capp"), charIDToTypeID("Ordn"), charIDToTypeID("Trgt") );
desc = executeActionGet(ref);
var brushList = desc.getList(stringIDToTypeID("presetManager")).getObjectValue(0).getList(charIDToTypeID("Nm "));
var Names = new Array();
for (var z = 1; z<brushList.count;z++){
try{
Names.push(brushList.getString(z));
}catch(e){alert(e);return;}
}
return Names;
};
[/CODE]