Append Notes Count to Task Folders

launch_agent.plist

<!-- Runs script every 5 minutes -->
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>Label</key>
    <string>notes-app-tasks-pending-count.job</string>
    <key>ProgramArguments</key>
    <array>
        <string>/usr/bin/osascript</string>
        <string>[PATH_TO_SCRIPT]/notes_count.scpt</string>
    </array>
    <key>StartInterval</key>
    <integer>300</integer>
</dict>
</plist>

notes_count.scpt

tell application "Notes"
  set taskFolders to every folder whose name contains "Tasks - Pending"
  repeat with taskFolder in taskFolders
    set originalName to taskFolder's name
    set cleanName to (do shell script "sed -E 's/[ ]?\\([0-9].*)//' <<<" & quoted form of originalName)
    set taskFolder's name to (cleanName & " (" & (count of taskFolder's notes) & ")")
  end repeat
end tell