diff --git a/codex-rs/otel/src/traces/otel_manager.rs b/codex-rs/otel/src/traces/otel_manager.rs
index 2b490bbb3..a1aaf0b51 100644
--- a/codex-rs/otel/src/traces/otel_manager.rs
+++ b/codex-rs/otel/src/traces/otel_manager.rs
@@ -446,6 +446,11 @@ impl OtelManager {
             1,
             &[("tool", tool_name), ("success", success_str)],
         );
+        self.record_duration(
+            "codex.tool.call.duration_ms",
+            duration,
+            &[("tool", tool_name), ("success", success_str)],
+        );
         tracing::event!(
             tracing::Level::INFO,
             event.name = "codex.tool_result",