DOCS-15819 updates for tech review feedback

Author: kanchana-mongodb

source/reference/aggregation-variables.txt

@@ -109,10 +109,11 @@ MongoDB offers the following system variables:
 
    * - .. variable:: SEARCH_META 
 
-     - A variable that stores the metadata results of an Atlas Search 
-       query. In a :pipeline:`$project` stage, a field set to the 
-       variable :variable:`$$SEARCH_META` returns the :atlas:`metadata 
-       results </reference/atlas-search/query-syntax/#metadata-result-types>`
+     - A variable that stores the metadata results of an :atlas:`Atlas 
+       Search </atlas-search/>` query. In all supported aggregation 
+       pipeline stages, a field set to the variable 
+       :variable:`$$SEARCH_META` returns the :atlas:`metadata results 
+       </reference/atlas-search/query-syntax/#metadata-result-types>`
        for the query.
 
        For an example of its usage, see Atlas Search :atlas:`facet