Try following
<?php
foreach ($this->getAttributes() as $_attribute){
echo $_attribute->getTooltip();
}
?>
UPDATE
$attribute_code = $_data['code'];
$attribute_details = Mage::getSingleton("eav/config")->getAttribute('catalog_product', $attribute_code);
$attribute = $attribute_details->getData(); // returns array
echo "<pre>";
print_r($attribute);