[plugins] Additional gating for tool suggest and apps. (#15573)

- [x] Additional gating for tool suggest and apps.

codex-rs/core/src/tools/spec.rs

@@ -389,7 +389,10 @@ impl ToolsConfig {
         let include_default_mode_request_user_input =
             include_request_user_input && features.enabled(Feature::DefaultModeRequestUserInput);
         let include_search_tool = model_info.supports_search_tool;
-        let include_tool_suggest = include_search_tool && features.enabled(Feature::ToolSuggest);
+        let include_tool_suggest = include_search_tool
+            && features.enabled(Feature::ToolSuggest)
+            && features.enabled(Feature::Apps)
+            && features.enabled(Feature::Plugins);
         let include_original_image_detail = can_request_original_image_detail(features, model_info);
         let include_artifact_tools =
             features.enabled(Feature::Artifact) && codex_artifacts::can_manage_artifact_runtime();

codex-rs/core/src/tools/spec_tests.rs

@@ -2031,6 +2031,7 @@ fn tool_suggest_is_not_registered_without_feature_flag() {
     let model_info = search_capable_model_info();
     let mut features = Features::with_defaults();
     features.enable(Feature::Apps);
+    features.enable(Feature::Plugins);
     let available_models = Vec::new();
     let tools_config = ToolsConfig::new(&ToolsConfigParams {
         model_info: &model_info,
@@ -2061,6 +2062,52 @@ fn tool_suggest_is_not_registered_without_feature_flag() {
     );
 }
 
+#[test]
+fn tool_suggest_requires_apps_and_plugins_features() {
+    let model_info = search_capable_model_info();
+    let discoverable_tools = Some(vec![discoverable_connector(
+        "connector_2128aebfecb84f64a069897515042a44",
+        "Google Calendar",
+        "Plan events and schedules.",
+    )]);
+    let available_models = Vec::new();
+
+    for disabled_feature in [Feature::Apps, Feature::Plugins] {
+        let mut features = Features::with_defaults();
+        features.enable(Feature::ToolSuggest);
+        for feature in [Feature::Apps, Feature::Plugins] {
+            if feature != disabled_feature {
+                features.enable(feature);
+            }
+        }
+
+        let tools_config = ToolsConfig::new(&ToolsConfigParams {
+            model_info: &model_info,
+            available_models: &available_models,
+            features: &features,
+            web_search_mode: Some(WebSearchMode::Cached),
+            session_source: SessionSource::Cli,
+            sandbox_policy: &SandboxPolicy::DangerFullAccess,
+            windows_sandbox_level: WindowsSandboxLevel::Disabled,
+        });
+        let (tools, _) = build_specs_with_discoverable_tools(
+            &tools_config,
+            None,
+            None,
+            discoverable_tools.clone(),
+            &[],
+        )
+        .build();
+
+        assert!(
+            !tools
+                .iter()
+                .any(|tool| tool_name(&tool.spec) == TOOL_SUGGEST_TOOL_NAME),
+            "tool_suggest should be absent when {disabled_feature:?} is disabled"
+        );
+    }
+}
+
 #[test]
 fn search_tool_description_handles_no_enabled_apps() {
     let model_info = search_capable_model_info();
@@ -2205,6 +2252,7 @@ fn tool_suggest_description_lists_discoverable_tools() {
     let model_info = search_capable_model_info();
     let mut features = Features::with_defaults();
     features.enable(Feature::Apps);
+    features.enable(Feature::Plugins);
     features.enable(Feature::ToolSuggest);
     let available_models = Vec::new();
     let tools_config = ToolsConfig::new(&ToolsConfigParams {