The goal of this trick to add a little little bit of functionality to the workflow of light agents. By notifying regular agent within Zendesk that a light agent has read/responded to the ticket.
We're going to leverage triggers for this, and expand the definition of pending/on-hold a little bit.
Set-up the trigger
Create a new trigger with the following conditions

conditions
- Ticket: update via is e-mail
- Ticket: comment is private
- Ticket: comment text contains the following string !status open
- Ticket: status is open
or
- Ticket: status is on-hold
actions
- Ticket: status is open
Save the trigger.
How to use it
Whenever an agent wants a response from a light agent they should add them in CC or @mention them. For this case our advise is to use the status on-hold or pending, so the assigned agent knows they have to wait for someone to reply.
Teach the light agent to use !status open somewhere in their reponse to make the ticket change status to open. Because of the trigger this will now happen.
(Unfortunately it's not possible to use the same syntax as the MAIL api, since Zendesk will strip that of the body and ignore it for end-users or light agents)
Enjoy!


