Placeholder tags in Chat Shortcuts

Hello there! 

I am trying to add placeholder tags to Chat Shortcuts for the user's first name and the agent's first name

When editing the shortcut, there is an option to “Insert placeholder” underneath the content box. The placeholder tags available are:

{{visitor_name}}

{{agent_name}}

However, these placeholder tags add the user's first name and last name and the agent's first and last name, which is quite inconvenient, as the agents have to manually delete the last names.

I have also tried with the following placeholder tags:

{{visitor.first_name}}

{{agent.first_name}}

{{visitor_first_name}}

{{agent_first_name}}

{{ticket.assignee.first_name}}

{{ticket.requester.first_name}}

But these ones don't work at all.

Is there any way to correctly add the placeholder tags in the Shortcuts for the user's first name and the agent's first name?

Thank you!