How to prevent smart diagram from hyphenating?

the simplest method for suppressing hyphenation within a group is this:

within the local group for the command, add

\hyphenpenalty10000
\exhyphenpenalty10000

these are the settings to suppress hyphenation using the primitive attributes that govern hyphenation of ordinary words and words that already contain hyphens, respectively. when you exit the group, the values are automatically restored to the usual for the body text.

A quick workaround is to use command \mbox{not hyphenated}, because this command does not allow an hyphenation of included word(s).

Or you can use \\ to force a newline inside the description.

Or you can use command \hyphenation{...} to force that the listed word(s) is/are not hyphenated in the complete document. The word Donaudampfschifffahrt is a long german word I used to show the effect ...

Please see the following MWE (see marking <======):

\documentclass{article}
\hyphenation{Donaudampfschifffahrt}% <==================================
\usepackage{smartdiagram}
\begin{document}
\smartdiagramset{description title text width=1.5cm,
  description text width=7cm,description width=8cm}
\smartdiagram[descriptive diagram]{
  {x,the contribution to the \mbox{projection} Xxxxxxxxx Xxxxx}% <==============
}

\smartdiagram[descriptive diagram]{
  {x,the contribution to the projection\\ Xxxxxxxxx Xxxxx}% <==============
}

\smartdiagram[descriptive diagram]{
  {x,the contribution to the Donaudampfschifffahrt\\ Xxxxxxxxx Xxxxx}% <==============
}
\end{document}

and the result: