diff --git a/src/providers/registry.ts b/src/providers/registry.ts
index 78e645d029..fd13fcfabe 100644
--- a/src/providers/registry.ts
+++ b/src/providers/registry.ts
@@ -1394,7 +1394,9 @@ export const PROVIDER_REGISTRY: readonly ProviderRegistryEntry[] = [
     // the map above. Key-auth declared the same value via keyAuthServiceTier, so the key
     // lane is unchanged.
     chatServiceTier: true,
-    fastTierDescription: "Priority processing, 2x token price",
+    // Shared across key and OAuth catalog rows. OAuth subscription has no
+    // per-token price, so the 2x claim is scoped to key auth.
+    fastTierDescription: "Priority processing; tier pricing applies on key auth only",
     featured: true,
     oauthId: "xai",
     jawcodeBundle: "xai",
diff --git a/tests/codex-integration/codex-catalog.test.ts b/tests/codex-integration/codex-catalog.test.ts
index 482e3f022b..cae7a2d00f 100644
--- a/tests/codex-integration/codex-catalog.test.ts
+++ b/tests/codex-integration/codex-catalog.test.ts
@@ -2043,7 +2043,7 @@ describe("provider discovered model display names", () => {
       // Classified by the 2026-09-13 OAuth-lane probe: grok-4.6 is Fast-eligible on
       // either xAI transport, so the hint fills the capability and its description.
       supportsServiceTier: true,
-      fastTierDescription: "Priority processing, 2x token price",
+      fastTierDescription: "Priority processing; tier pricing applies on key auth only",
     });
     expect(catalogModelSlug(output)).toBe("xai/grok-4.6");
   });
diff --git a/tests/service/service-tier-capability.test.ts b/tests/service/service-tier-capability.test.ts
index efd7797ae2..febdfc7a6e 100644
--- a/tests/service/service-tier-capability.test.ts
+++ b/tests/service/service-tier-capability.test.ts
@@ -129,7 +129,7 @@ describe("xAI Fast capability follows the captured authentication transport", ()
       capability: true,
       eligibility: "eligible",
       forwardCallerTier: true,
-      fastTierDescription: "Priority processing, 2x token price",
+      fastTierDescription: "Priority processing; tier pricing applies on key auth only",
     });
 
     const oauthPolicy = fastPolicyForModel(xaiProvider("oauth"), "grok-4.6", "xai");
@@ -155,7 +155,7 @@ describe("xAI Fast capability follows the captured authentication transport", ()
     expect(keyCatalog?.service_tiers).toEqual([{
       id: "priority",
       name: "Fast",
-      description: "Priority processing, 2x token price",
+      description: "Priority processing; tier pricing applies on key auth only",
     }]);
     expect(keyCatalog?.additional_speed_tiers).toEqual(["fast"]);
     expect(decideTier(keyPolicy, true, undefined)).toEqual({ kind: "set", value: "priority" });
@@ -167,7 +167,7 @@ describe("xAI Fast capability follows the captured authentication transport", ()
     expect(oauthCatalog?.service_tiers).toEqual([{
       id: "priority",
       name: "Fast",
-      description: "Priority processing, 2x token price",
+      description: "Priority processing; tier pricing applies on key auth only",
     }]);
     expect(oauthCatalog?.additional_speed_tiers).toEqual(["fast"]);
     expect(decideTier(oauthPolicy, true, undefined)).toEqual({ kind: "set", value: "priority" });