WARNING: VIDEO-ONLY: The downloaded file MUST have a `video/*` content-type
            (e.g. video/mp4, video/quicktime). GIFs and image formats are
            rejected — use `upload_image_creative` for those.

            WARNING: WHEN YOU NEED TO CALL THIS:
            Call this BEFORE `create_update_video_ad` ONLY when you don't already
            have a videoLibraryId. If the user (or an earlier step) has
            already given you a creativeID for the video, skip the upload
            and pass that id straight to `create_update_video_ad`.

            WORKFLOW INTEGRATION (when an upload IS needed):
            1. Upload your video URL with this tool → response contains the integer `id` (the videoLibraryId).
            2. Pass that integer `id` as `creativeID` in `create_update_video_ad`.

            COMMON WORKFLOWS:
            - Upload existing video → Get videoLibraryId → Use as creativeID in `create_update_video_ad`.
            - For Reddit VIDEO ads, ALSO upload a thumbnail image via `upload_image_creative` and pass that image
              library id as `redditThumbnailLibraryId` to `create_update_video_ad`.

            REQUIRED PARAMETERS:
            - videos: Array of video URLs to upload.

            OPTIONAL PARAMETERS:
            - thumbnail_library_id: Existing imageLibraryId to attach to the
              uploaded video as its platform thumbnail. Most callers don't
              need this — Reddit VIDEO ads handle thumbnails at ad-creation
              time via `redditThumbnailLibraryId`, not here.
            - usage_type: "CTV" to upload the video for a LinkedIn CTV
              (Connected TV) ad. The platform then validates the file as CTV
              inventory (6 to 60 seconds, 1920x1080 or 1280x720, at most
              500 MB; LinkedIn recommends exactly 15, 30, 45 or 60 seconds)
              and only such an upload can back `create_update_ctv_ad`. A
              non-compliant file is rejected at upload with the platform's
              reason. Omit for in-feed video ads.

            VIDEO REQUIREMENTS:
            - URLs must be valid and publicly accessible.
            - Supported formats: MP4 (recommended), MOV, and other video/* MIME types.
            - For GIFs (image/gif): use `upload_image_creative` instead.

            RESPONSE FORMAT:
            Returns array of objects, one per video. `id` is returned as a
            string (the platform's library ids are integers but the upload
            response stringifies them); pass it to `create_update_video_ad` as an
            integer (Python `int(id)` if you need the cast).
            [
                {
                    "url": "https://example.com/video.mp4",
                    "name": "video.mp4",
                    "id": "12345",                # videoLibraryId — use as creativeID in create_update_video_ad
                    "success": true
                },
                {
                    "url": "https://example.com/bad.mp4",
                    "name": "bad.mp4",
                    "id": null,
                    "success": false,
                    "error": "Download failed: Connection timeout"
                }
            ]

            CHANNEL READINESS: success and id mean the platform library accepted
            the file. Meta uploads are asynchronous and may still be UPLOADING.
            Use fetch_creative_details to read per-channel status; a Facebook or
            Instagram VIDEO ad must wait until that channel is READY.

            ERROR HANDLING:
            - If one upload fails, others continue.
            - Each result includes a success flag and (on failure) an error message.
            - A content-type that does not start with `video/` is rejected
              with a clear error pointing the caller at `upload_image_creative`.