Laravel not responding with validator errors

I validate a model

$validator = $c->validate($collection);

This is the validate function

public function validate($data){
    return Validator::make($data, $this->rules());;
}

These are the rules

public function rules() {

    return  array([
        'name' => [
            'required', 'You need to choose a name for your collection.',
            'unique:collections,table_name', 'A collection or collection table with this name already exists'
        ],
           ...
        ]);
}

I'm trying to send back a JSON response with the validator's errors, as such:

return response()->json($validator->errors(), 200);     

I'm currently testing validation for the 'name' rule, and the validator is failing, as expected.

However, I'm expecting it to return that rule's message ("A collection or collection table with this name already exists")

Instead, I'm getting this returned:

My goal is to have laravel send back the error that I need, thank you in advance for any help.

---

edit: updated code:

Messages:

public function messages(){
return [
'name.required' => 'A name must be specified for the collection',
'name.unique' => 'A collection or collection table with this name already exists',
'name.min' => 'The collection name is too short',
'fields.*.fieldName.unique' => 'Field names must be unique',
'fields.*.fieldName.required' => 'One or more fields must be specified for the collection',
'fields.*.fieldName.not_in' => 'Illegal field name, please try another one',
'fields.*.fieldName.min' => 'The field name is too short',
'fields.*.dataType.required' => 'A data-type must be specified for fields',
'fields.*.dataType.in' => 'Illegal data-type'
];

}

public function rules() {

    return  array([
        'name' => [
        'required', 'You need to choose a name for your collection.',
        'unique:collections,table_name', 'A collection or collection table 
with this name already exists',
        'min:2'
        ],
        'fields.*.fieldName' =>  
        [       
        'unique' => 'Please ensure that the fields are uniquely named.',
        'required' => 'You must specify a name for your fields.',
        'not_in:'.implode(',', self::$illegalFieldNames),
        'min:2'
        ],

        'fields.*.dataType' =>
        [
        'required', 'You must specify a data type for your fields.',
        'in:'.implode(',', self::$allowedDataTypes)
        ]

        ]);
}


public function validate($data){

    return Validator::make($data, $this->rules(), $this->messages());
}

via Barry D.