diff --git a/pkg/builtin/builtin.go b/pkg/builtin/builtin.go
index 228ffb66..819f6f20 100644
--- a/pkg/builtin/builtin.go
+++ b/pkg/builtin/builtin.go
@@ -114,7 +114,7 @@ var tools = map[string]types.Tool{
 		Parameters: types.Parameters{
 			Description: "Concludes the conversation. This can not be used to ask a question.",
 			Arguments: types.ObjectSchema(
-				"summary", "A summary of the dialog",
+				"return", "The instructed value to return or a summary of the dialog if no value is instructed",
 			),
 		},
 		BuiltinFunc: SysChatFinish,
@@ -640,7 +640,7 @@ func (e *ErrChatFinish) Error() string {
 
 func SysChatFinish(ctx context.Context, env []string, input string) (string, error) {
 	var params struct {
-		Message string `json:"summary,omitempty"`
+		Message string `json:"return,omitempty"`
 	}
 	if err := json.Unmarshal([]byte(input), &params); err != nil {
 		return "", &ErrChatFinish{
diff --git a/pkg/tests/runner_test.go b/pkg/tests/runner_test.go
index ea450b53..700d965a 100644
--- a/pkg/tests/runner_test.go
+++ b/pkg/tests/runner_test.go
@@ -64,7 +64,7 @@ func TestDualSubChat(t *testing.T) {
 	r.RespondWith(tester.Result{
 		Func: types.CompletionFunctionCall{
 			Name:      types.ToolNormalizer("sys.chat.finish"),
-			Arguments: `{"summary":"Chat done"}`,
+			Arguments: `{"return":"Chat done"}`,
 		},
 	})
 
@@ -89,7 +89,7 @@ func TestDualSubChat(t *testing.T) {
 	r.RespondWith(tester.Result{
 		Func: types.CompletionFunctionCall{
 			Name:      types.ToolNormalizer("sys.chat.finish"),
-			Arguments: `{"summary":"Chat done2"}`,
+			Arguments: `{"return":"Chat done2"}`,
 		},
 	}, tester.Result{
 		Text: "And we're done",
diff --git a/pkg/tests/testdata/TestContextSubChat/call2.golden b/pkg/tests/testdata/TestContextSubChat/call2.golden
index 18ef5c00..2d29bfc8 100644
--- a/pkg/tests/testdata/TestContextSubChat/call2.golden
+++ b/pkg/tests/testdata/TestContextSubChat/call2.golden
@@ -9,8 +9,8 @@
         "description": "Concludes the conversation. This can not be used to ask a question.",
         "parameters": {
           "properties": {
-            "summary": {
-              "description": "A summary of the dialog",
+            "return": {
+              "description": "The instructed value to return or a summary of the dialog if no value is instructed",
               "type": "string"
             }
           },
diff --git a/pkg/tests/testdata/TestContextSubChat/call3.golden b/pkg/tests/testdata/TestContextSubChat/call3.golden
index 095b280d..cf2a4c29 100644
--- a/pkg/tests/testdata/TestContextSubChat/call3.golden
+++ b/pkg/tests/testdata/TestContextSubChat/call3.golden
@@ -9,8 +9,8 @@
         "description": "Concludes the conversation. This can not be used to ask a question.",
         "parameters": {
           "properties": {
-            "summary": {
-              "description": "A summary of the dialog",
+            "return": {
+              "description": "The instructed value to return or a summary of the dialog if no value is instructed",
               "type": "string"
             }
           },
diff --git a/pkg/tests/testdata/TestContextSubChat/call7.golden b/pkg/tests/testdata/TestContextSubChat/call7.golden
index ff4a2842..d12c4297 100644
--- a/pkg/tests/testdata/TestContextSubChat/call7.golden
+++ b/pkg/tests/testdata/TestContextSubChat/call7.golden
@@ -9,8 +9,8 @@
         "description": "Concludes the conversation. This can not be used to ask a question.",
         "parameters": {
           "properties": {
-            "summary": {
-              "description": "A summary of the dialog",
+            "return": {
+              "description": "The instructed value to return or a summary of the dialog if no value is instructed",
               "type": "string"
             }
           },
diff --git a/pkg/tests/testdata/TestContextSubChat/call8.golden b/pkg/tests/testdata/TestContextSubChat/call8.golden
index 5c647cbd..8cbffd87 100644
--- a/pkg/tests/testdata/TestContextSubChat/call8.golden
+++ b/pkg/tests/testdata/TestContextSubChat/call8.golden
@@ -9,8 +9,8 @@
         "description": "Concludes the conversation. This can not be used to ask a question.",
         "parameters": {
           "properties": {
-            "summary": {
-              "description": "A summary of the dialog",
+            "return": {
+              "description": "The instructed value to return or a summary of the dialog if no value is instructed",
               "type": "string"
             }
           },
diff --git a/pkg/tests/testdata/TestContextSubChat/step1.golden b/pkg/tests/testdata/TestContextSubChat/step1.golden
index 39c65251..53ef8e7b 100644
--- a/pkg/tests/testdata/TestContextSubChat/step1.golden
+++ b/pkg/tests/testdata/TestContextSubChat/step1.golden
@@ -86,8 +86,8 @@
                         "description": "Concludes the conversation. This can not be used to ask a question.",
                         "parameters": {
                           "properties": {
-                            "summary": {
-                              "description": "A summary of the dialog",
+                            "return": {
+                              "description": "The instructed value to return or a summary of the dialog if no value is instructed",
                               "type": "string"
                             }
                           },
diff --git a/pkg/tests/testdata/TestContextSubChat/step3.golden b/pkg/tests/testdata/TestContextSubChat/step3.golden
index 2c900ace..e8fbfcfb 100644
--- a/pkg/tests/testdata/TestContextSubChat/step3.golden
+++ b/pkg/tests/testdata/TestContextSubChat/step3.golden
@@ -130,8 +130,8 @@
                         "description": "Concludes the conversation. This can not be used to ask a question.",
                         "parameters": {
                           "properties": {
-                            "summary": {
-                              "description": "A summary of the dialog",
+                            "return": {
+                              "description": "The instructed value to return or a summary of the dialog if no value is instructed",
                               "type": "string"
                             }
                           },
diff --git a/pkg/tests/testdata/TestDualSubChat/call2.golden b/pkg/tests/testdata/TestDualSubChat/call2.golden
index 18ef5c00..2d29bfc8 100644
--- a/pkg/tests/testdata/TestDualSubChat/call2.golden
+++ b/pkg/tests/testdata/TestDualSubChat/call2.golden
@@ -9,8 +9,8 @@
         "description": "Concludes the conversation. This can not be used to ask a question.",
         "parameters": {
           "properties": {
-            "summary": {
-              "description": "A summary of the dialog",
+            "return": {
+              "description": "The instructed value to return or a summary of the dialog if no value is instructed",
               "type": "string"
             }
           },
diff --git a/pkg/tests/testdata/TestDualSubChat/call3.golden b/pkg/tests/testdata/TestDualSubChat/call3.golden
index 2359072b..415c8332 100644
--- a/pkg/tests/testdata/TestDualSubChat/call3.golden
+++ b/pkg/tests/testdata/TestDualSubChat/call3.golden
@@ -9,8 +9,8 @@
         "description": "Concludes the conversation. This can not be used to ask a question.",
         "parameters": {
           "properties": {
-            "summary": {
-              "description": "A summary of the dialog",
+            "return": {
+              "description": "The instructed value to return or a summary of the dialog if no value is instructed",
               "type": "string"
             }
           },
diff --git a/pkg/tests/testdata/TestDualSubChat/call4.golden b/pkg/tests/testdata/TestDualSubChat/call4.golden
index 84dfacc9..f1fa4ecf 100644
--- a/pkg/tests/testdata/TestDualSubChat/call4.golden
+++ b/pkg/tests/testdata/TestDualSubChat/call4.golden
@@ -9,8 +9,8 @@
         "description": "Concludes the conversation. This can not be used to ask a question.",
         "parameters": {
           "properties": {
-            "summary": {
-              "description": "A summary of the dialog",
+            "return": {
+              "description": "The instructed value to return or a summary of the dialog if no value is instructed",
               "type": "string"
             }
           },
diff --git a/pkg/tests/testdata/TestDualSubChat/call5.golden b/pkg/tests/testdata/TestDualSubChat/call5.golden
index efaffb32..165a064b 100644
--- a/pkg/tests/testdata/TestDualSubChat/call5.golden
+++ b/pkg/tests/testdata/TestDualSubChat/call5.golden
@@ -9,8 +9,8 @@
         "description": "Concludes the conversation. This can not be used to ask a question.",
         "parameters": {
           "properties": {
-            "summary": {
-              "description": "A summary of the dialog",
+            "return": {
+              "description": "The instructed value to return or a summary of the dialog if no value is instructed",
               "type": "string"
             }
           },
diff --git a/pkg/tests/testdata/TestDualSubChat/call6.golden b/pkg/tests/testdata/TestDualSubChat/call6.golden
index fbc2db55..69bf9804 100644
--- a/pkg/tests/testdata/TestDualSubChat/call6.golden
+++ b/pkg/tests/testdata/TestDualSubChat/call6.golden
@@ -9,8 +9,8 @@
         "description": "Concludes the conversation. This can not be used to ask a question.",
         "parameters": {
           "properties": {
-            "summary": {
-              "description": "A summary of the dialog",
+            "return": {
+              "description": "The instructed value to return or a summary of the dialog if no value is instructed",
               "type": "string"
             }
           },
diff --git a/pkg/tests/testdata/TestDualSubChat/step1.golden b/pkg/tests/testdata/TestDualSubChat/step1.golden
index 6e3075b3..c02e67a9 100644
--- a/pkg/tests/testdata/TestDualSubChat/step1.golden
+++ b/pkg/tests/testdata/TestDualSubChat/step1.golden
@@ -123,8 +123,8 @@
                       "description": "Concludes the conversation. This can not be used to ask a question.",
                       "parameters": {
                         "properties": {
-                          "summary": {
-                            "description": "A summary of the dialog",
+                          "return": {
+                            "description": "The instructed value to return or a summary of the dialog if no value is instructed",
                             "type": "string"
                           }
                         },
@@ -189,8 +189,8 @@
                       "description": "Concludes the conversation. This can not be used to ask a question.",
                       "parameters": {
                         "properties": {
-                          "summary": {
-                            "description": "A summary of the dialog",
+                          "return": {
+                            "description": "The instructed value to return or a summary of the dialog if no value is instructed",
                             "type": "string"
                           }
                         },
diff --git a/pkg/tests/testdata/TestDualSubChat/step2.golden b/pkg/tests/testdata/TestDualSubChat/step2.golden
index c21a49c9..0f090762 100644
--- a/pkg/tests/testdata/TestDualSubChat/step2.golden
+++ b/pkg/tests/testdata/TestDualSubChat/step2.golden
@@ -130,8 +130,8 @@
                       "description": "Concludes the conversation. This can not be used to ask a question.",
                       "parameters": {
                         "properties": {
-                          "summary": {
-                            "description": "A summary of the dialog",
+                          "return": {
+                            "description": "The instructed value to return or a summary of the dialog if no value is instructed",
                             "type": "string"
                           }
                         },
diff --git a/pkg/tests/testdata/TestDualSubChat/step3.golden b/pkg/tests/testdata/TestDualSubChat/step3.golden
index 959d66c2..a35becd7 100644
--- a/pkg/tests/testdata/TestDualSubChat/step3.golden
+++ b/pkg/tests/testdata/TestDualSubChat/step3.golden
@@ -130,8 +130,8 @@
                       "description": "Concludes the conversation. This can not be used to ask a question.",
                       "parameters": {
                         "properties": {
-                          "summary": {
-                            "description": "A summary of the dialog",
+                          "return": {
+                            "description": "The instructed value to return or a summary of the dialog if no value is instructed",
                             "type": "string"
                           }
                         },