failing _validation, but _search works

gistfile1.txt

curl -s -XGET 'http://localhost:9200/4af9aae4-7ec1-458d-8c50-692ddb0f2c6d/msg,file,file-info/_validate/query?explain=true' -d '{"fields":["id"],"filter":{"not":{"and":[{"numeric_range":{"msg-size":{"gte":1000}}},{"query":{"prefix":{"content-type.verbatim":"application/"}}}]}}}' | python -mjson.tool
{
    "_shards": {
        "failed": 0, 
        "successful": 1, 
        "total": 1
    }, 
    "explanations": [
        {
            "error": "org.elasticsearch.index.query.QueryParsingException: [4af9aae4-7ec1-458d-8c50-692ddb0f2c6d-0] request does not support [fields]", 
            "index": "4af9aae4-7ec1-458d-8c50-692ddb0f2c6d-0", 
            "valid": false
        }
    ], 
    "valid": false
}

# removing fields, it reports that query does not support filter

curl -s -XGET 'http://localhost:9200/4af9aae4-7ec1-458d-8c50-692ddb0f2c6d/msg,file,file-info/_validate/query?explain=true' -d '{"filter":{"not":{"and":[{"numeric_range":{"msg-size":{"gte":1000}}},{"query":{"prefix":{"content-type.verbatim":"application/"}}}]}}}' | python -mjson.tool
{
    "_shards": {
        "failed": 0, 
        "successful": 1, 
        "total": 1
    }, 
    "explanations": [
        {
            "error": "org.elasticsearch.index.query.QueryParsingException: [4af9aae4-7ec1-458d-8c50-692ddb0f2c6d-0] request does not support [filter]", 
            "index": "4af9aae4-7ec1-458d-8c50-692ddb0f2c6d-0", 
            "valid": false
        }
    ], 
    "valid": false
}

# some queries work with validate API

curl -s -XGET 'http://localhost:9200/4af9aae4-7ec1-458d-8c50-692ddb0f2c6d/msg,file,file-info/_validate/query?explain=true' -d '{"query": { "match": { "name": "PLEASE READ: something not important" }}}' | python -mjson.tool
{                                                                                                                                                                                                                                             
    "_shards": {                                                                                                                                                                                                                              
        "failed": 0,                                                                                                                                                                                                                          
        "successful": 1,                                                                                                                                                                                                                      
        "total": 1                                                                                                                                                                                                                            
    },                                                                                                                                                                                                                                        
    "explanations": [                                                                                                                                                                                                                         
        {                                                                                                                                                                                                                                     
            "explanation": "filtered(name:PLEASE READ: something not important)->cache(_type:file _type:file-info _type:msg)",                                                                                                       
            "index": "4af9aae4-7ec1-458d-8c50-692ddb0f2c6d-0",                                                                                                                                                                                
            "valid": true                                                                                                                                                                                                                     
        }                                                                                                                                                                                                                                     
    ],                                                                                                                                                                                                                                        
    "valid": true                                                                                                                                                                                                                             
}