Hacker way )

When the file is saved (if the anotations changed you need to save the file, you do not need to close it), you can open the binary document file through the script and find the "8BIMAnno" tag. After it you will find the structure from which you can pull out the number of annotations, and by the tags "txtC" and "txtA" pull out the text and the author of the annotations.

I will look into it today to see what I can do, as that was some time ago I wrote it and not remember well how that worked.

EDIT:

Another first of this kind script you will not find other like it on this and Create notes/annotations? - PS-SCRIPTS.COM forums (and probably nowhere ). It works extremaly fast with even many channels, paths and layer(Set)s beside notes. Only first time it takes 1/5 second while every next just 100 ms (40 for saving, 25 reading, and 20 for searching by RegEx).

For those who didn't read earlier posts: you can record this script as last item of your action. It's going to create 'note' with number of times a file was processed and name of its parent folder (remove .name in aD.path.name if you want full path).

$.level = 0; try {
     pth = (aD = activeDocument).path; function sTT(v) {return stringIDToTypeID(v)}
     with(psd = new PhotoshopSaveOptions()) {
          annotations = !(alphaChannels = embedColorProfile = layers = spotColors = false)
     }
     aD.saveAs(fle = File('~/desktop/.psd'), psd, true)
     function anno() {
          fle.open('r'); var r = fle.read(); fle.close(), fle.remove()
          var r = r.match(/txtC.{3,6}(\n.{2})?((?:\x00.)+)?/g)
          if (r) {for(i = 0; i < l = r.length; i++) {
               if (n = r.slice(10, i == l - 1 ? r.length : -4).match(/[^\x00]/g))
               {if (/#\d+/.test(n = n.join(''))) return parseFloat(n.slice(1)) + 1}
          }}
     }
     if (arr = ['horizontal', 'vertical'], !(n = anno())) {
          (ref1 = new ActionReference()).putClass(sTT('annotation'));
          (dsc1 = new ActionDescriptor()).putReference(sTT('null'), ref1)
          u = (p = preferences).rulerUnits, p.rulerUnits = Units.PIXELS
          for(dsc3 = new ActionDescriptor(), j = 0; j < arr.length; j++) {
               dsc3.putUnitDouble(sTT(arr), sTT('pixelsUnit'),
               eval('aD.' + (!j ? 'width' : 'height') +'.value * 19 / 20'))
          } p.rulerUnits = u;
          (dsc2 = new ActionDescriptor()).putObject(sTT('location'), sTT('paint'), dsc3)
          dsc2.putEnumerated(aT = sTT('annotType'), aT, sTT('annotText')), dsc1.putObject
          (sTT('using'), sTT('annotation'), dsc2), executeAction(sTT('make'), dsc1, DialogModes.NO);
     }
     number = '#' + (n || 0) + ' & ' + pth.name;
     (ref1 = new ActionReference()).putIndex(sTT('annotation'), i); (dsc1 = new ActionDescriptor())
     .putReference(sTT('null'), ref1); (dsc2 = new ActionDescriptor()).putString(sTT('text'), number)
     dsc1.putObject(sTT('to'), sTT('annotation'), dsc2), executeAction(sTT('set'), dsc1, DialogModes.NO)
}
catch (err) {alert(err.message)}