diff --git a/.changeset/3965-list-creative-formats-handler.md b/.changeset/3965-list-creative-formats-handler.md
new file mode 100644
index 0000000000..99e059731d
--- /dev/null
+++ b/.changeset/3965-list-creative-formats-handler.md
@@ -0,0 +1,29 @@
+---
+---
+
+fix(training-agent): wire listCreativeFormats on /creative and /creative-builder tenants — closes #3965 Class F
+
+The v6 `CreativeAdServerPlatform` (used by `/creative` tenant) and `CreativeBuilderPlatform` (used by `/creative-builder` tenant) didn't expose `listCreativeFormats`. The v5 handler `handleListCreativeFormats` exists and the `/sales` tenant already wires it through; the two creative tenants were missing the wiring.
+
+Symptom: `pagination_integrity_creative_formats` storyboard failed on the `first_page` step with `UNSUPPORTED_FEATURE: list_creative_formats: this creative platform did not implement listCreativeFormats. Add listCreativeFormats(req, ctx) to your CreativeBu...`
+
+Storyboard adoption catalog (`tool-catalog.ts`) was already updated in #3962 to advertise `list_creative_formats` on `creative` and `creative-builder` — that change reflected the SDK's framework-registration. This PR fills in the actual handler the framework dispatches to.
+
+**Files:**
+- `server/src/training-agent/v6-creative-platform.ts`: import `handleListCreativeFormats`, add `listCreativeFormats` method on `creative` interface.
+- `server/src/training-agent/v6-creative-builder-platform.ts`: same shape.
+
+**Per-tenant impact (post overlay-cache):**
+- `/creative`: 56/67 clean / 69 passed → **64/67 clean / 79 passed** (+8 clean, +10 passed)
+- `/creative-builder`: 52/67 clean / 51 passed → **58/67 clean / 61 passed** (+6 clean, +10 passed)
+
+Floor raises land in a follow-up after #3974 (the Class B+D fix-up that already raises floors) merges, to avoid conflict.
+
+**Related #3965 catch-up state after this PR:**
+- ✅ Class B (UNKNOWN_SCENARIO error coarsening) — #3974
+- ✅ Class D (idempotency_key dead capture) — #3974
+- ✅ Class F (seed_creative_format / listCreativeFormats handler) — this PR
+- ✅ Class G (REFERENCE_NOT_FOUND) — was a stale-cache phantom, source already correct
+- 🟡 Class A (comply_test_controller context echo) — adcp-client#1455 (SDK gap)
+- 🟡 Class C (signed_requests /mcp-strict discovery) — predates the bump
+- 🟡 Class E (force_create_media_buy_arm directive shape) — needs reproducer
diff --git a/server/src/training-agent/v6-creative-builder-platform.ts b/server/src/training-agent/v6-creative-builder-platform.ts
index 8dbbde185e..651d65c525 100644
--- a/server/src/training-agent/v6-creative-builder-platform.ts
+++ b/server/src/training-agent/v6-creative-builder-platform.ts
@@ -23,6 +23,7 @@ import {
 import {
   handleBuildCreative,
   handlePreviewCreative,
+  handleListCreativeFormats,
   handleSyncCreatives,
 } from './task-handlers.js';
 import type { ToolArgs, TrainingContext } from './types.js';
@@ -131,6 +132,10 @@ export class TrainingCreativeBuilderPlatform
       const result = await handlePreviewCreative(req as ToolArgs, buildTrainingCtx(ctx.account));
       return translateV5Result(result);
     },
+    listCreativeFormats: async (req, ctx) => {
+      const result = await handleListCreativeFormats(req as ToolArgs, buildTrainingCtx(ctx.account));
+      return translateV5Result(result);
+    },
     syncCreatives: async (creatives, ctx) => {
       const result = await handleSyncCreatives({ creatives } as unknown as ToolArgs, buildTrainingCtx(ctx.account));
       const wrapped = translateV5Result<{ creatives?: unknown[] }>(result);
diff --git a/server/src/training-agent/v6-creative-platform.ts b/server/src/training-agent/v6-creative-platform.ts
index 955bfcdb25..3200175d54 100644
--- a/server/src/training-agent/v6-creative-platform.ts
+++ b/server/src/training-agent/v6-creative-platform.ts
@@ -19,6 +19,7 @@ import {
   handleBuildCreative,
   handlePreviewCreative,
   handleListCreatives,
+  handleListCreativeFormats,
   handleGetCreativeDelivery,
   handleSyncCreatives,
 } from './task-handlers.js';
@@ -129,6 +130,10 @@ export class TrainingCreativePlatform
       const result = await handleListCreatives(req as ToolArgs, buildTrainingCtx(ctx.account));
       return translateV5Result(result);
     },
+    listCreativeFormats: async (req, ctx) => {
+      const result = await handleListCreativeFormats(req as ToolArgs, buildTrainingCtx(ctx.account));
+      return translateV5Result(result);
+    },
     getCreativeDelivery: async (filter, ctx) => {
       const result = await handleGetCreativeDelivery(filter as ToolArgs, buildTrainingCtx(ctx.account));
       return translateV5Result(result);