Add a title and description. Including #Shorts in the title or description can help the algorithm identify it, though it is not strictly required if the video is vertical and under 60 seconds. Best Practices for Writing Shorts
For videos under 60 seconds, aim for a script of 30–45 seconds to leave room for visual pacing and prevent going over the limit. Youtube Shorts mp4
Maximum 60 seconds (though some tools allow up to 180 seconds, 60 is the standard for mobile creation). How to Upload an MP4 as a Short Add a title and description
Place your primary keywords in the first three lines of the description, as these are the most visible to the algorithm. Youtube Shorts mp4