How to Produce a Valid Token

Question

I'm trying to create a custom token. I've already successfully implemented hook_token_info, and the token shows up. However, whenever I insert a the token [site:chosen-school-year] wherever I'm able, it doesn't show up.

Here's the code to implement the token:

function capstone_tokens_tokens($type, $tokens, array $data = array(), array $options = array()){
    $replacements = array();
    $sanitize = !empty($options['sanitize']);

    if ($type = 'site'){
        foreach ($tokens as $name => $original) {
            switch($name){
            case 'chosen-school-year':
                $replacements[$original] = getSelectedSchoolYear();
                break;
            }
        }   
    }

    return $replacements;
}

getSelectedSchoolYear() is a function that I use in a different location that works as it's meant to.

I've compared my code to the samples provided here and here, and haven't found any clear discrepancies between my code and theirs. I have tried clearing the Drupal cache, but that didn't provide any results. Is there something else in the system that I should be checking/trying?