Fix optional question param

Signed-off-by: Nathalie Jonathan <[email protected]>

Author: nathaliellenaa

ml-algorithms/src/main/java/org/opensearch/ml/engine/tools/IndexMappingTool.java

@@ -226,7 +226,7 @@ public void init(Client client) {
 
         @Override
         public IndexMappingTool create(Map<String, Object> params) {
-            ConfigurationUtils.readStringProperty(TYPE, null, params, "question");
+            ConfigurationUtils.readOptionalStringProperty(TYPE, null, params, "question");
             ConfigurationUtils.readOptionalList(TYPE, null, params, "index");
             ConfigurationUtils.readBooleanProperty(TYPE, null, params, "local", false);
 

ml-algorithms/src/main/java/org/opensearch/ml/engine/tools/ListIndexTool.java

@@ -468,7 +468,7 @@ public void init(Client client, ClusterService clusterService) {
 
         @Override
         public ListIndexTool create(Map<String, Object> params) {
-            ConfigurationUtils.readStringProperty(TYPE, null, params, "question");
+            ConfigurationUtils.readOptionalStringProperty(TYPE, null, params, "question");
             ConfigurationUtils.readOptionalList(TYPE, null, params, "indices");
             ConfigurationUtils.readBooleanProperty(TYPE, null, params, "local", false);
             ConfigurationUtils.readIntProperty(TYPE, null, params, "page_size", 100);