Add a QML snippet such as

PropertyAction with targets

which will expand to this:

 PropertyAction { target: name; property: "name"; value: value }

Now, when the caret is in target: name, and the user edits "name", also the property field's value changes.

Other such snippets include, but may not be limited to:
states, transitions, State, Transition and NumberAnimation. For all animation snippets, both "with target" and "with targets" snippets have this broken autocompletion of the second field.