Aliasing the rm command to avoid evaluating separate asterisks

I would like to use the rm command such that it returns an error when there is a separate asterisk in its argument. For example, if I type rm -f * .txt , then this command should not be executed (this way I have already removed several files unintentionally). Could you please help me what the simplest way is to do this?

As discussed in comments, there is normally no way for an rm alias or function to detect if it was run with a * that was expanded by the shell to a list of arguments. This Bash function demonstrates a possible alternative way to help with your problem:

function rm
{
    local arg
    for arg in "$@"; do
        if [[ $arg != -* && ! -L $arg && ! -e $arg ]]; then
            printf 'rm: ERROR: argument does not exist: %q\n' "$arg" >&2
            printf '    Nothing is being removed\n' >&2
            return 1
        fi
    done

    command rm "$@"
}

• The function checks all of its arguments. It prints an error message and returns immediately with non-zero status if any of them isn't an option, isn't a symlink, and isn't an ordinary file, directory, or special file. The explicit check for a symlink is necessary because a symlink to a non-existing path fails the -e test. For instance, if run with rm * .txt it will delete nothing because it will detect a non-existing .txt file.
• If none of the arguments fails the checks, it runs the real rm on the full list of arguments.