The "What" parameter is best when applied a single keyword or key phrase.
You can find tag IDs via previous searches. We do not have a META data API for this data, but plan on in the future.
<tag id="11238" primary="false">Bar Scene</tag>
<tag id="11201" primary="false">Sushi</tag>
<tag id="11202" primary="false">Japanese</tag>
<tag id="11234" primary="false">$$$$</tag>
<tag id="11204" primary="false">Brazilian</tag>
<tag id="11256" primary="false">Date Spot</tag>
<tag id="11269" primary="false">Group Dining</tag>
<tag id="11367" primary="false">Open 7 Days</tag>
<tag id="11298" primary="false">People Watching</tag>