diff --git a/src/main/java/org/opensearch/agent/tools/SearchIndexTool.java b/src/main/java/org/opensearch/agent/tools/SearchIndexTool.java
index ff34718e..c7577501 100644
--- a/src/main/java/org/opensearch/agent/tools/SearchIndexTool.java
+++ b/src/main/java/org/opensearch/agent/tools/SearchIndexTool.java
@@ -12,6 +12,7 @@
 import java.security.PrivilegedExceptionAction;
 import java.util.Map;
 import java.util.Objects;
+import java.util.Optional;
 
 import org.opensearch.action.search.SearchRequest;
 import org.opensearch.action.search.SearchResponse;
@@ -30,6 +31,7 @@
 import org.opensearch.search.SearchHit;
 import org.opensearch.search.builder.SearchSourceBuilder;
 
+import com.google.gson.JsonElement;
 import com.google.gson.JsonObject;
 
 import lombok.Getter;
@@ -48,7 +50,7 @@ public class SearchIndexTool implements Tool {
 
     public static final String TYPE = "SearchIndexTool";
     private static final String DEFAULT_DESCRIPTION =
-        "Use this tool to search an index by providing two parameters: 'index' for the index name, and 'query' for the OpenSearch DSL formatted query.";
+        "Use this tool to search an index by providing two parameters: 'index' for the index name, and 'query' for the OpenSearch DSL formatted query. Only use this tool when a DSL query is available.";
 
     private String name = TYPE;
 
@@ -90,23 +92,13 @@ public <T> void run(Map<String, String> parameters, ActionListener<T> listener)
         try {
             String input = parameters.get(INPUT_FIELD);
             JsonObject jsonObject = StringUtils.gson.fromJson(input, JsonObject.class);
-            String index = jsonObject.get(INDEX_FIELD).getAsString();
-            String query = jsonObject.get(QUERY_FIELD).toString();
-
-            SearchRequest searchRequest;
-            try {
-                searchRequest = getSearchRequest(index, query);
-            } catch (Exception e1) {
-                try {
-                    // try different json parsing method
-                    query = jsonObject.get(QUERY_FIELD).getAsString();
-                    searchRequest = getSearchRequest(index, query);
-                } catch (Exception e2) {
-                    // try wrapped query
-                    query = "{\"query\": " + query + "}";
-                    searchRequest = getSearchRequest(index, query);
-                }
+            String index = Optional.ofNullable(jsonObject).map(x -> x.get(INDEX_FIELD)).map(JsonElement::getAsString).orElse(null);
+            String query = Optional.ofNullable(jsonObject).map(x -> x.get(QUERY_FIELD)).map(JsonElement::toString).orElse(null);
+            if (index == null || query == null) {
+                listener.onFailure(new IllegalArgumentException("SearchIndexTool's two parameter: index and query are required!"));
+                return;
             }
+            SearchRequest searchRequest = getSearchRequest(index, query);
 
             ActionListener<SearchResponse> actionListener = ActionListener.<SearchResponse>wrap(r -> {
                 SearchHit[] hits = r.getHits().getHits();
diff --git a/src/test/java/org/opensearch/agent/tools/SearchIndexToolTests.java b/src/test/java/org/opensearch/agent/tools/SearchIndexToolTests.java
index 6de9fbfc..d228c0cb 100644
--- a/src/test/java/org/opensearch/agent/tools/SearchIndexToolTests.java
+++ b/src/test/java/org/opensearch/agent/tools/SearchIndexToolTests.java
@@ -94,7 +94,7 @@ public void testRunWithNormalIndex() {
 
     @Test
     public void testRunWithConnectorIndex() {
-        String inputString = "{\"index\": \".plugins-ml-connector\", \"query\": {\"match_all\": {}}}";
+        String inputString = "{\"index\": \".plugins-ml-connector\", \"query\": {\"query\": {\"match_all\": {}}}}";
         Map<String, String> parameters = Map.of("input", inputString);
         mockedSearchIndexTool.run(parameters, null);
         Mockito.verify(client, never()).search(any(), any());
@@ -103,7 +103,7 @@ public void testRunWithConnectorIndex() {
 
     @Test
     public void testRunWithModelIndex() {
-        String inputString = "{\"index\": \".plugins-ml-model\", \"query\": {\"match_all\": {}}}";
+        String inputString = "{\"index\": \".plugins-ml-model\", \"query\": {\"query\": {\"match_all\": {}}}}";
         Map<String, String> parameters = Map.of("input", inputString);
         mockedSearchIndexTool.run(parameters, null);
         Mockito.verify(client, never()).search(any(), any());
@@ -112,7 +112,7 @@ public void testRunWithModelIndex() {
 
     @Test
     public void testRunWithModelGroupIndex() {
-        String inputString = "{\"index\": \".plugins-ml-model-group\", \"query\": {\"match_all\": {}}}";
+        String inputString = "{\"index\": \".plugins-ml-model-group\", \"query\": {\"query\": {\"match_all\": {}}}}";
         Map<String, String> parameters = Map.of("input", inputString);
         mockedSearchIndexTool.run(parameters, null);
         Mockito.verify(client, never()).search(any(), any());
@@ -133,7 +133,7 @@ public void testRunWithSearchResults() {
             return null;
         }).when(client).search(any(), any());
 
-        String inputString = "{\"index\": \"test-index\", \"query\": {\"match_all\": {}}}";
+        String inputString = "{\"index\": \"test-index\", \"query\": {\"query\": {\"match_all\": {}}}}";
         final CompletableFuture<String> future = new CompletableFuture<>();
         ActionListener<String> listener = ActionListener.wrap(r -> { future.complete(r); }, e -> { future.completeExceptionally(e); });
         Map<String, String> parameters = Map.of("input", inputString);
@@ -168,24 +168,13 @@ public void testRunWithInvalidQuery() {
 
     @Test
     public void testRunWithEmptyQueryBody() {
-        // this empty query should be parsed with jsonObject.get(QUERY_FIELD).getAsString();
-        String inputString = "{\"index\": \"test-index\", \"query\": \"{}\"}";
+        String inputString = "{\"index\": \"test-index\", \"query\": {}}";
         Map<String, String> parameters = Map.of("input", inputString);
         mockedSearchIndexTool.run(parameters, null);
         Mockito.verify(client, times(1)).search(any(), any());
         Mockito.verify(client, Mockito.never()).execute(any(), any(), any());
     }
 
-    @Test
-    public void testRunWithWrappedQuery() {
-        // this query should be wrapped liked "{\"query\": " + query + "}"
-        String inputString = "{\"index\": \".plugins-ml-model\", \"query\": {\"match_all\": {}}}";
-        Map<String, String> parameters = Map.of("input", inputString);
-        mockedSearchIndexTool.run(parameters, null);
-        Mockito.verify(client, never()).search(any(), any());
-        Mockito.verify(client, times(1)).execute(eq(MLModelSearchAction.INSTANCE), any(), any());
-    }
-
     @Test
     public void testFactory() {
         SearchIndexTool searchIndexTool = SearchIndexTool.Factory.getInstance().create(Collections.emptyMap());