feat: restrict spawn_agent v2 to messages (#16325)

codex-rs/tools/src/agent_tool.rs

@@ -66,7 +66,7 @@ pub fn create_spawn_agent_tool_v2(options: SpawnAgentToolOptions<'_>) -> ToolSpe
         defer_loading: None,
         parameters: JsonSchema::Object {
             properties,
-            required: Some(vec!["task_name".to_string()]),
+            required: Some(vec!["task_name".to_string(), "items".to_string()]),
             additional_properties: Some(false.into()),
         },
         output_schema: Some(spawn_agent_output_schema_v2()),
@@ -594,15 +594,6 @@ fn spawn_agent_common_properties_v1(agent_type_description: &str) -> BTreeMap<St
 
 fn spawn_agent_common_properties_v2(agent_type_description: &str) -> BTreeMap<String, JsonSchema> {
     BTreeMap::from([
-        (
-            "message".to_string(),
-            JsonSchema::String {
-                description: Some(
-                    "Initial plain-text task for the new agent. Use either message or items."
-                        .to_string(),
-                ),
-            },
-        ),
         ("items".to_string(), create_collab_input_items_schema()),
         (
             "agent_type".to_string(),

codex-rs/tools/src/agent_tool_tests.rs

@@ -56,7 +56,9 @@ fn spawn_agent_tool_v2_requires_task_name_and_lists_visible_models() {
     assert!(description.contains("visible display (`visible-model`)"));
     assert!(!description.contains("hidden display (`hidden-model`)"));
     assert!(properties.contains_key("task_name"));
+    assert!(properties.contains_key("items"));
     assert!(properties.contains_key("fork_turns"));
+    assert!(!properties.contains_key("message"));
     assert!(!properties.contains_key("fork_context"));
     assert_eq!(
         properties.get("agent_type"),
@@ -64,7 +66,10 @@ fn spawn_agent_tool_v2_requires_task_name_and_lists_visible_models() {
             description: Some("role help".to_string()),
         })
     );
-    assert_eq!(required, Some(vec!["task_name".to_string()]));
+    assert_eq!(
+        required,
+        Some(vec!["task_name".to_string(), "items".to_string()])
+    );
     assert_eq!(
         output_schema.expect("spawn_agent output schema")["required"],
         json!(["agent_id", "task_name", "nickname"])