Sticker alt-text character limit is too low (accessibility concern)

The "description" field for a sticker is limited to 100 characters. This is not nearly long enough.

When attempting to write an accessible description for a sticker, my goal is to communicate all the visual information present in the sticker using only words. It's very difficult to do so with only 100 characters or less, because a lot of stickers are memes or characters or etc that rely on visual context.

For instance, consider the following sticker (which I hope uploads properly...):

It could be described as "neko arc cosplaying as astolfo" (30 characters), but that description relies on the reader knowing both who neko arc is and who astolfo is. It also doesn't describe which of astolfo's outfits neko arc is wearing. It also presumes that this character is in fact neko arc, rather than just a neko-ified astolfo.

A description that fixes these problems might be something like:

"a chibi anime character giving a thumbs up. they have pink hair, cat ears, and oval-shaped eyes with pink pupils. they are wearing a purple hoodie, striped belly shirt, black skirt, black leggings, and purple leather shoes. they have a pink cat's tail."

The outfit, colors, and details are important because the communicate a sort of "personality" for the sticker; why someone chose this sticker rather than another. But, that's 252 characters... so I have to write a worse description.

This is also an issue with joke/meme stickers. A lot of jokes are spoiled if you type out the punchline, so it'd be better if you described it gradually, in the order the viewer perceives them. But there aren't enough characters to do that. :(