I’m not sure that this answers your question about hiding parameters of a discord command, but I think it may give you some ideas on how you could implement your bet command in terms of your other game commands without needing to do so much argument parsing.

I have two suggestions. Think of coin_toss as a sub-routine of your bet function or implement a shared logical implementation of your coin_toss function.

Coin Toss as a Sub-routine of Bet

import os
import random

from discord.ext import commands
from dotenv import load_dotenv

load_dotenv()

DISCORD_TOKEN = os.getenv("DISCORD_TOKEN")

bot = commands.Bot(command_prefix="//")


@bot.command()
async def coin_toss(ctx):
    outcomes = ("Heads", "Tails")
    result = outcomes[random.randint(0, 1)]
    await ctx.reply(result)
    return result


# Simulates your Utils Get Function
def get_commands():
    return [coin_toss]


def get_command_by_name(command_list, name):
    names = [c.name for c in command_list]
    if name not in names:
        return None
    else:
        return command_list[names.index(name)]


@bot.command()
async def bet(ctx, *args):
    if len(args) != 3:
        # Example //bet 15 Heads coin_toss
        await ctx.reply("Command is //bet amount outcome game_name")

    c = get_command_by_name(get_commands(), name=args[2])

    # Check Command Exists
    if c is None:
        await ctx.reply(f"Command {args[2]} does not exist")
    else:
        # Assumes result comes back as a string!!
        result = await c(ctx)
        # Compare case insensitive
        if result.lower() == args[1].lower():
            msg = f"Congratulation you won {args[0]}"
        else:
            msg = f'You lost your bet of {args[0]}'
        await ctx.reply(msg)


bot.run(DISCORD_TOKEN)

I have a simulated your get_commands, and your utils.get(self.get_commands(), name=value) functions here so please update your bet implementation to reflect how your functions actually perform. I’ve also done this outside of a class for ease of testing, but please make the necessary changes to incorporate this code into your current implementation.

The downside of this approach is the delay. You’re affectively sending two separate replies, once from the coin_toss function, then again from bet this can make for a delayed user experience.

Coin Toss with Shared Logical Implementation

import os
import random

from discord.ext import commands
from dotenv import load_dotenv

load_dotenv()

DISCORD_TOKEN = os.getenv("DISCORD_TOKEN")

bot = commands.Bot(command_prefix="//")


# Separated Game Logic from the Bot Command
def coin_toss_logic():
    outcomes = ("Heads", "Tails")
    result = outcomes[random.randint(0, 1)]
    return result


@bot.command()
async def coin_toss(ctx):
    await ctx.reply(coin_toss_logic())


# Simulates your Utils Get Function
def get_commands():
    return [coin_toss_logic]


def get_command_by_name(command_list, name):
    # Strip off the "_logic" portion of your command names
    # uses __name__ since not a command anymore
    # Requires a consistent naming convention!
    names = [c.__name__[:-6] for c in command_list]
    if name not in names:
        return None
    else:
        return command_list[names.index(name)]


@bot.command()
async def bet(ctx, *args):
    if len(args) != 3:
        # Example //bet 15 Heads coin_toss
        await ctx.reply("Command is //bet amount outcome game_name")

    c = get_command_by_name(get_commands(), name=args[2])

    # Check Command Exists
    if c is None:
        await ctx.reply(f"Command {args[2]} does not exist")
    else:
        # Assumes result comes back as a string!!
        # No await needed since it's not an asyc command
        result = c()
        # Need to add Result to msg since not handled by command anymore
        msg = f'{result}n'
        # Compare case insensitive
        if result.lower() == args[1].lower():
            msg += f"Congratulation you won {args[0]}"
        else:
            msg += f'You lost your bet of {args[0]}'
        await ctx.reply(msg)


bot.run(DISCORD_TOKEN)

The benefit of this implementation being that there is less delay between messages, however, there is more work because you have essentially two separate functions that both map to the same name.