You can do this by modifying the internals. I'm using 8.4, but I have no reason to think the 8.2 version will be much different.
open ..\c8\templates\ps\logicsheets\presentation\main\search.xsl
look for this section:
<out:variable name="field">
<out:variable name="f" select="string(key('env-param','sfield'))"/>
<out:choose>
<out:when test="$singleField != ''"><out:value-of select="$singleField"/></out:when>
<out:when test="($f = 'k' or $f = '')">
<out:choose>
<out:when test="$indexSearch='true' and $userCanUseIndexSearch">
<out:value-of select="'k'"/>
</out:when>
<out:otherwise>
<out:value-of select="'n'"/>
</out:otherwise>
</out:choose>
</out:when>
<out:otherwise>
<out:value-of select="$f"/>
</out:otherwise>
</out:choose>
</out:variable>
change the <out:value-of select="'n'"/> to <out:value-of select="'nd'"/>
Note, single quote inside double quote.
n is for Name
d is for Description
and nd is for Name and Description
I cannot stress enough the importance of backing up any internal file before modifying it! A single misplaced comma will often be enough to prevent Cognos from loading.