Unable to Convert to Object - AppSync Velocity Template - velocity

Question

My maps match the schema. I'm clearly just not understanding something. I'm a newbie to appsync, graphql, and velocity so I'm sure it's a simple mistake, but I've been going in circles for hours trying to figure out what I'm doing wrong.
Query
query MyQuery {
searchUSDAFoundationFoods(terms: "apple") {
uid
description
}
}
Response
{
"data": {
"searchUSDAFoundationFoods": null
},
"errors": [
{
"path": [
"searchUSDAFoundationFoods"
],
"data": null,
"errorType": "MappingTemplate",
"errorInfo": null,
"locations": [
{
"line": 2,
"column": 3,
"sourceName": null
}
],
"message": "Unable to convert \n[\n \n \n {\"uid\":\"usda-foundation-food-1105664\",\"description\":\"Apples, granny smith, with skin, raw\"}\n \n \n {\"uid\":\"usda-foundation-food-1105781\",\"description\":\"Apples, gala, with skin, raw\"}\n \n \n {\"uid\":\"usda-foundation-food-1105547\",\"description\":\"Apples, honeycrisp, with skin, raw\"}\n \n \n {\"uid\":\"usda-foundation-food-1105430\",\"description\":\"Apples, red delicious, with skin, raw\"}\n \n \n {\"uid\":\"usda-foundation-food-1105897\",\"description\":\"Apples, fuji, with skin, raw\"}\n] to Object."
}
]
}
Response Template
[
#foreach($entry in $context.result.hits.hits)
#set($myMap = {})
$util.qr($myMap.put("uid", $entry.get("_id")))
$util.qr($myMap.put("description", $entry.get("_source").get("description")))
$util.toJson($myMap)
#end
]
Schema
type FoodSearchResult {
uid: String
description: String
}
type Query {
searchUSDAFoundationFoods(terms: String): [FoodSearchResult]
}

Answer 1

It began working when I changed the response template to the following:
[
#foreach($entry in $context.result.hits.hits)
#set($myMap = {})
$util.qr($myMap.put("uid", $entry.get("_id")))
$util.qr($myMap.put("description", $entry.get("_source").get("description")))
#if( $velocityCount > 1 ) , #end
$util.toJson($myMap)
#end
]
The only change is the addition of the line:
#if( $velocityCount > 1 ) , #end
I noticed it in an example, but have found no clear explanation of what it is, how it works, or why it's needed in the velocity template programming guide on amazon's site, nor anywhere else.
Update:
The line is adding in the necessary commas to make the result valid JSON.