[plugins] Add a flag for tool search. (#15722)

- [x] Add a flag for tool search.

codex-rs/features/src/lib.rs

@@ -142,6 +142,8 @@ pub enum Feature {
     SpawnCsv,
     /// Enable apps.
     Apps,
+    /// Enable the tool_search tool for apps.
+    ToolSearch,
     /// Enable discoverable tool suggestions for apps.
     ToolSuggest,
     /// Enable plugins.
@@ -717,6 +719,12 @@ pub const FEATURES: &[FeatureSpec] = &[
         stage: Stage::Stable,
         default_enabled: true,
     },
+    FeatureSpec {
+        id: Feature::ToolSearch,
+        key: "tool_search",
+        stage: Stage::UnderDevelopment,
+        default_enabled: false,
+    },
     FeatureSpec {
         id: Feature::ToolSuggest,
         key: "tool_suggest",

codex-rs/features/src/tests.rs

@@ -120,6 +120,12 @@ fn tool_suggest_is_stable_and_enabled_by_default() {
     assert_eq!(Feature::ToolSuggest.default_enabled(), true);
 }
 
+#[test]
+fn tool_search_is_under_development_and_disabled_by_default() {
+    assert_eq!(Feature::ToolSearch.stage(), Stage::UnderDevelopment);
+    assert_eq!(Feature::ToolSearch.default_enabled(), false);
+}
+
 #[test]
 fn use_linux_sandbox_bwrap_is_a_removed_feature_key() {
     assert_eq!(