diff --git a/.github/copilot-instructions.md b/.github/copilot-instructions.md
index 168720d..aa12037 100644
--- a/.github/copilot-instructions.md
+++ b/.github/copilot-instructions.md
@@ -56,7 +56,7 @@ Each effect follows this structure:
 2. A dedicated `MonoBehaviour` runner (nested in the same file or a sibling file) spawned via `EffectRuntimeController.Instance.SpawnRunner<T>(...)` inside `TrySchedule`.
 3. The runner handles timing (start/end beat), per-frame updates in `LateUpdate`, and cleanup in `Stop`/`OnDisable`.
 4. Registration via `EffectDefinitionRegistry.Initialize(...)` using `Register(new YourEffect())`.
-5. Documentation media at `docs/effects/<effect-id>/preview.gif` and `docs/effects/<effect-id>/demo.mp4`, and an entry in `docs/effects/README.md`.
+5. A short `.mp4` preview video (uploaded to GitHub, not stored in the repository) showing the event selected with its properties and the effect being applied in the editor, with the link included in `docs/effects/README.md` under the **Preview** section. Since agents cannot run the game to record this, include the following placeholder instead and leave it for the PR author to replace: `<!-- TODO: record preview .mp4 in-game, upload to GitHub, and replace this placeholder with the link -->`.
 
 **Handling effect conflicts and concurrent instances:**
 - Before implementing a new effect, consider how it interacts with all existing effects when running simultaneously.
diff --git a/README.md b/README.md
index f7af0f1..fbe43f6 100644
--- a/README.md
+++ b/README.md
@@ -47,10 +47,8 @@ If `BepInExPluginsDir` exists, build output is copied there automatically.
 4. Add a dedicated runtime runner `MonoBehaviour` for the effect (in the same file or a sibling file).
 5. Implement `TrySchedule` to read entity properties and spawn your runner through `EffectRuntimeController.Instance.SpawnRunner<T>(...)`.
 6. Register the effect once in `EffectDefinitionRegistry.Initialize(...)` using `Register(new YourEffect())`.
-7. Add media for documentation:
-   - `docs/effects/<effect-id>/preview.gif`
-   - `docs/effects/<effect-id>/demo.mp4`
-8. Update `docs/effects/README.md`.
+7. Record a short `.mp4` preview video showing the event selected with its properties and the effect being applied in the editor. Upload it to GitHub (e.g. by attaching it to a PR comment or issue) and copy the resulting link.
+8. Update `docs/effects/README.md` and include the uploaded video link under the **Preview** section for the new effect.
 
 ### Pull requests