This is specifically for developers to set up as it's done by adjusting the javascript code on the page.
You can insert javascript on to the page so that during a co-browsing session the agent sees a reminder prompt but the customer does not.
Example
Directly below is the javascript code you would add to a page on which you wish to remind the agent to say something when you've reached that page during a co-browsing session.
Upscope('updateConnection', {agentPrompt: "On this page, remind them of the ability to turn off typing if they wish"})
What will the support agent see? The grey box to the right shows the text they'll be prompted with. The customer does not see this.
You can use that code to create prompts when you arrive at a page or when a user clicks a button or other element on that page.