diff --git a/ml-algorithms/src/main/java/org/opensearch/ml/engine/algorithms/agent/AgentUtils.java b/ml-algorithms/src/main/java/org/opensearch/ml/engine/algorithms/agent/AgentUtils.java
index d8f8d6da94..c748866ede 100644
--- a/ml-algorithms/src/main/java/org/opensearch/ml/engine/algorithms/agent/AgentUtils.java
+++ b/ml-algorithms/src/main/java/org/opensearch/ml/engine/algorithms/agent/AgentUtils.java
@@ -472,6 +472,11 @@ public static Map<String, String> constructToolParams(
         if (toolSpecConfigMap != null) {
             toolParams.putAll(toolSpecConfigMap);
         }
+        toolParams.put("action_input", actionInput);
+        if (isJson(actionInput)) {
+            Map<String, String> params = getParameterMap(gson.fromJson(actionInput, Map.class));
+            toolParams.putAll(params);
+        }
         if (tools.get(action).useOriginalInput()) {
             toolParams.put("input", question);
             lastActionInput.set(question);
@@ -486,10 +491,6 @@ public static Map<String, String> constructToolParams(
             }
         } else {
             toolParams.put("input", actionInput);
-            if (isJson(actionInput)) {
-                Map<String, String> params = getParameterMap(gson.fromJson(actionInput, Map.class));
-                toolParams.putAll(params);
-            }
         }
         return toolParams;
     }
diff --git a/ml-algorithms/src/test/java/org/opensearch/ml/engine/algorithms/agent/AgentUtilsTest.java b/ml-algorithms/src/test/java/org/opensearch/ml/engine/algorithms/agent/AgentUtilsTest.java
index 496ce00136..b42763321f 100644
--- a/ml-algorithms/src/test/java/org/opensearch/ml/engine/algorithms/agent/AgentUtilsTest.java
+++ b/ml-algorithms/src/test/java/org/opensearch/ml/engine/algorithms/agent/AgentUtilsTest.java
@@ -603,11 +603,12 @@ public void testConstructToolParams() {
         String question = "dummy question";
         String actionInput = "{'detectorName': 'abc', 'indices': 'sample-data' }";
         verifyConstructToolParams(question, actionInput, (toolParams) -> {
-            Assert.assertEquals(4, toolParams.size());
+            Assert.assertEquals(5, toolParams.size());
             Assert.assertEquals(actionInput, toolParams.get("input"));
             Assert.assertEquals("abc", toolParams.get("detectorName"));
             Assert.assertEquals("sample-data", toolParams.get("indices"));
             Assert.assertEquals("value1", toolParams.get("key1"));
+            Assert.assertEquals(actionInput, toolParams.get("action_input"));
         });
     }
 
@@ -617,12 +618,65 @@ public void testConstructToolParams_UseOriginalInput() {
         String actionInput = "{'detectorName': 'abc', 'indices': 'sample-data' }";
         when(tool1.useOriginalInput()).thenReturn(true);
         verifyConstructToolParams(question, actionInput, (toolParams) -> {
-            Assert.assertEquals(2, toolParams.size());
+            Assert.assertEquals(5, toolParams.size());
             Assert.assertEquals(question, toolParams.get("input"));
             Assert.assertEquals("value1", toolParams.get("key1"));
+            Assert.assertEquals(actionInput, toolParams.get("action_input"));
+            Assert.assertEquals("sample-data", toolParams.get("indices"));
+            Assert.assertEquals("abc", toolParams.get("detectorName"));
         });
     }
 
+    @Test
+    public void testConstructToolParams_PlaceholderConfigInput() {
+        String question = "dummy question";
+        String actionInput = "action input";
+        String preConfigInputStr = "Config Input: ";
+        Map<String, Tool> tools = Map.of("tool1", tool1);
+        Map<String, MLToolSpec> toolSpecMap = Map
+            .of(
+                "tool1",
+                MLToolSpec
+                    .builder()
+                    .type("tool1")
+                    .parameters(Map.of("key1", "value1"))
+                    .configMap(Map.of("input", preConfigInputStr + "${parameters.action_input}"))
+                    .build()
+            );
+        AtomicReference<String> lastActionInput = new AtomicReference<>();
+        String action = "tool1";
+        Map<String, String> toolParams = AgentUtils.constructToolParams(tools, toolSpecMap, question, lastActionInput, action, actionInput);
+        Assert.assertEquals(3, toolParams.size());
+        Assert.assertEquals(preConfigInputStr + actionInput, toolParams.get("input"));
+        Assert.assertEquals("value1", toolParams.get("key1"));
+        Assert.assertEquals(actionInput, toolParams.get("action_input"));
+    }
+
+    @Test
+    public void testConstructToolParams_PlaceholderConfigInputJson() {
+        String question = "dummy question";
+        String actionInput = "{'detectorName': 'abc', 'indices': 'sample-data' }";
+        String preConfigInputStr = "Config Input: ";
+        Map<String, Tool> tools = Map.of("tool1", tool1);
+        Map<String, MLToolSpec> toolSpecMap = Map
+            .of(
+                "tool1",
+                MLToolSpec
+                    .builder()
+                    .type("tool1")
+                    .parameters(Map.of("key1", "value1"))
+                    .configMap(Map.of("input", preConfigInputStr + "${parameters.detectorName}"))
+                    .build()
+            );
+        AtomicReference<String> lastActionInput = new AtomicReference<>();
+        String action = "tool1";
+        Map<String, String> toolParams = AgentUtils.constructToolParams(tools, toolSpecMap, question, lastActionInput, action, actionInput);
+        Assert.assertEquals(5, toolParams.size());
+        Assert.assertEquals(preConfigInputStr + "abc", toolParams.get("input"));
+        Assert.assertEquals("value1", toolParams.get("key1"));
+        Assert.assertEquals(actionInput, toolParams.get("action_input"));
+    }
+
     private void verifyConstructToolParams(String question, String actionInput, Consumer<Map<String, String>> verify) {
         Map<String, Tool> tools = Map.of("tool1", tool1);
         Map<String, MLToolSpec> toolSpecMap = Map