Help with using buttons inside the inventory interface

I am currently trying to implement a simple button (look) inside the inventory, so items can be inspected.

Therefore, I created a command button in the inventory interface and set its action so whenever someone presses the button, the current command is changed to the look command. In the items section, I then created an action for the item in my inventory 

Execution type : Executed command ->

Command : Look command

Item : [empty]

and that some text appears (this is a key) when the look command is used. When I hover over the item, it shows that the "link" between item and command is correctly working (e.g. command text is look at and item text is key, it shows "look at key" ,  however as soon as I use left click on that item, it doesn't show the text that should appear (this is a key). 

I also tried using this command button on items in my scene and created the identical action for the item as described above, where it works without problems. I also tried to see if there was a problem with the item itself, so instead of using the Execution type : Executed command -> in the item actions, I just selected right click, which also worked without any problems. What am I doing wrong ?

Thanks for your help in advance!!