diff --git a/codex-rs/core/src/tools/spec_plan.rs b/codex-rs/core/src/tools/spec_plan.rs
index 9d789113ad..5d5d0c7bc9 100644
--- a/codex-rs/core/src/tools/spec_plan.rs
+++ b/codex-rs/core/src/tools/spec_plan.rs
@@ -1163,6 +1163,14 @@ fn add_core_utility_tools(context: &CoreToolPlanContext<'_>, registry: &mut Tool
         {
             registry.add(SleepHandler);
         }
+    } else if context
+        .model_info
+        .experimental_supported_tools
+        .iter()
+        .any(|tool| tool == "clock")
+    {
+        registry.add(CurrentTimeHandler);
+        registry.add(SleepHandler);
     }
 
     if tool_suggest_enabled(turn_context)
diff --git a/codex-rs/core/tests/suite/current_time_reminder.rs b/codex-rs/core/tests/suite/current_time_reminder.rs
index fa06d98192..400adc0500 100644
--- a/codex-rs/core/tests/suite/current_time_reminder.rs
+++ b/codex-rs/core/tests/suite/current_time_reminder.rs
@@ -59,6 +59,7 @@ enum ClockSetup {
     Configured,
     Persistent,
     OrdinaryEffort,
+    ModelTools,
     ExplicitlyDisabled,
     RequiredOff,
 }
@@ -338,6 +339,7 @@ async fn current_time_reminders_can_follow_only_user_or_tool_outputs() -> Result
 #[test_case(ClockSetup::Configured; "configured")]
 #[test_case(ClockSetup::Persistent; "persistent")]
 #[test_case(ClockSetup::OrdinaryEffort; "ordinary_effort")]
+#[test_case(ClockSetup::ModelTools; "model_tools_without_reminders")]
 #[test_case(ClockSetup::ExplicitlyDisabled; "explicitly_disabled")]
 #[test_case(ClockSetup::RequiredOff; "required_off")]
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
@@ -351,10 +353,17 @@ async fn system_time_source_adds_current_time_reminder(clock_setup: ClockSetup)
     )
     .await;
     let mut builder = test_codex()
+        .with_model_info_override("gpt-5.5", move |model_info| {
+            if matches!(clock_setup, ClockSetup::Configured | ClockSetup::ModelTools) {
+                model_info
+                    .experimental_supported_tools
+                    .push("clock".to_string());
+            }
+        })
         .with_pre_build_hook(move |home| {
             let config = match clock_setup {
                 ClockSetup::Configured => Some("[features]\ncurrent_time_reminder = true\n"),
-                ClockSetup::ExplicitlyDisabled => {
+                ClockSetup::ModelTools | ClockSetup::ExplicitlyDisabled => {
                     Some("[features]\ncurrent_time_reminder = false\n")
                 }
                 ClockSetup::Persistent | ClockSetup::OrdinaryEffort | ClockSetup::RequiredOff => {
@@ -369,7 +378,7 @@ async fn system_time_source_adds_current_time_reminder(clock_setup: ClockSetup)
         .with_config(move |config| {
             config.include_environment_context = false;
             config.model_reasoning_effort = Some(match clock_setup {
-                ClockSetup::OrdinaryEffort => ReasoningEffort::High,
+                ClockSetup::OrdinaryEffort | ClockSetup::ModelTools => ReasoningEffort::High,
                 ClockSetup::Configured
                 | ClockSetup::Persistent
                 | ClockSetup::ExplicitlyDisabled
@@ -392,7 +401,7 @@ async fn system_time_source_adds_current_time_reminder(clock_setup: ClockSetup)
         ["curr_time", "sleep"].map(|name| request.tool_by_name("clock", name).is_some()),
         match clock_setup {
             ClockSetup::Configured => [true, false],
-            ClockSetup::Persistent => [true, true],
+            ClockSetup::Persistent | ClockSetup::ModelTools => [true, true],
             ClockSetup::OrdinaryEffort
             | ClockSetup::ExplicitlyDisabled
             | ClockSetup::RequiredOff => [false, false],
@@ -400,7 +409,10 @@ async fn system_time_source_adds_current_time_reminder(clock_setup: ClockSetup)
     );
     if matches!(
         clock_setup,
-        ClockSetup::OrdinaryEffort | ClockSetup::ExplicitlyDisabled | ClockSetup::RequiredOff
+        ClockSetup::OrdinaryEffort
+            | ClockSetup::ModelTools
+            | ClockSetup::ExplicitlyDisabled
+            | ClockSetup::RequiredOff
     ) {
         assert!(current_time_reminders(&request).is_empty());
         return Ok(());