Application protocol allows to open a dedicated application when using a specific url-like link (See technical documentation).

XrmToolBox can be used with application protocol so that it is possible to click on links with target like xrmtoolbox: 

The content after xrmtoolbox: must be url encoded and can contains the following switches:
  • /plugin:"Name of the tool"
  • /connection:"Name of the connection"
  • /data:"Data to pass to a IMessageBusHost tool"
For example, if you need to open the tool A Sample Tool with the connection named DEMO with data Hello World, you should build the following switches:
/plugin:"A Sample Tool" /connection:"DEMO" /data:"Hello World"

Which, once url encoded looks like:
%2Fplugin%3A%22A%20Sample%20Tool%22%20%2Fconnection%3A%22DEMO%22%20%2Fdata%3A%22Hello%20World%22

You can then create a link to open XrmToolBox with these parameters:
a href="xrmtoolbox:%2Fplugin%3A%22A%20Sample%20Tool%22%20%2Fconnection%3A%22DEMO%22%20%2Fdata%3A%22Hello%20World%22">Open XrmToolBox Sample Tool for connection Demo and sample data

When clicking on such a link, the browser asks permission to open the targeted application