There already is a hint that exists that informs the player why their attack failed for recovery moves at those HP values where they would fail. I don't have a replay offhand, but the message is "In Gen 1, recovery moves fail if (user's maximum HP - user's current HP + 1) is divisible by 256."
If you're talking about prompting the player when they select their action for the turn, I would be strongly against this. We're not trying to hand-hold players into "whoops, you didn't know about this mechanic before you clicked the move! here you go!". For example, we don't prompt a player to nudge them away from clicking Thunderbolt if your ally has LightningRod, or Fake Out on a grounded target in Psychic Terrain, or a non-super effective attack into Wonder Guard, or Poltergeist if the opponent's item has already been removed, or Substitute if your HP is below 25%, or dozens and dozens of other situations. Part of the skill of competitive Pokemon is understanding battle mechanics, and Gen 1 is full of unintuitive quirks. If the player doesn't understand the mechanics and chooses a move that would fail, that's on them.