# Add arrow to a descriptive diagram with smartdiagram

I would like to add an arrow to the following diagram.

The diagram is generated using http://www.texample.net/tikz/examples/smart-description/

Like this?

\documentclass[border=10pt]{standalone}
\usepackage{smartdiagram}
\tikzset{every picture/.append style={remember picture}}
\begin{document}
\hspace*{1cm}\smartdiagram[descriptive diagram]{
and line styles for nodes and arrows}},
{Position, {Place nodes using a matrix,
relative or absolute positioning}},
{Relation, Insert edges or arrows
between selected nodes},
{Label, Add labels on edges or arrows}}
\begin{tikzpicture}[overlay]
\draw[-stealth,line width=1mm,green!40]
(module-title4.west) to[out=120,in=-120] (module-title1.west);
\end{tikzpicture}
\end{document}


What's going on here? smartdiagram gives the nodes names which can be inferred from page 5 of the manual:

With \tikzset{every picture/.append style={remember picture}} one makes sure that these nodes do not get forgotten, and then one can access them with an overlay picture and do whatever one likes. Since you are using the standalone class and overlay does not extend the bounding box, I added \hspace*{1cm} to make sure the arrow does not get clipped away. The same strategy has been used here but without the explanation how one can obtain the node names, simply because back then I got them from the code rather than the manual.