BadHTTPResponse(response.status, text, response) telegram bot api

Question

I have an inline bot that gets a string from the user(inline mode) and sends back some data. This is my code:

# -*- coding: utf-8 -*-
import sys
import time
import telepot

from telepot.loop import MessageLoop
from telepot.namedtuple import *
from pprint import pprint
from elasticsearch import Elasticsearch
from mongoengine import connect

from model import *
from setting import *

bot = telepot.Bot(TOKEN)
es = Elasticsearch()
connect('poem')

content_type, chat_type, chat_id = None, None, None

def handle(msg):
    global content_type, chat_type, chat_id
    content_type, chat_type, chat_id = telepot.glance(msg)
    pprint(msg)


def on_inline_query(msg):
    query_id, from_id, query_string = telepot.glance(msg, flavor='inline_query')
    print ('Inline Query:', msg)
    response = es.search(
        index="poem",
        body={
            "query": {
                "match": {"text": query_string},
            }
        }
    )
    articles = []
    for index, hit in enumerate(response['hits']['hits']):
        poem = GanjoorPoemModel.objects(id=hit['_source']['poem_id']).first()
        header = u"%s\n%s" % (hit['_source']['poet'], hit['_source']['book'])
        if len(poem.sub_book):
            for sub in poem.sub_book:
                header += u"\n%s" % sub
        header += u"\n----\n"
        link = poem.link
        text = header + poem.text
        if len(text) > 4096:
            temp = poem.text[:(4096-len(header)-len(link)-10)] + "\n" + link
            text = header + temp
        print "A", str(poem.link)
        # text = text.encode('utf-8', 'ignore').decode('utf-8')
        iqra = InlineQueryResultArticle(
            id=str(index) + "_" + hit['_source']['poem_id'],
            title=u"%s-%s" %(hit['_source']['poet'], hit['_source']['book']),
            input_message_content=InputTextMessageContent(
                message_text=text
            ),
            description=hit['_source']['text'],
            thumb_url='https://appreview.ir/wp-content/uploads/com.example.mohammad.books_.png'
        )
        articles.append(iqra)
    bot.answerInlineQuery(query_id, articles, cache_time=5)

def on_chosen_inline_result(msg):
    result_id, from_id, query_string = telepot.glance(msg, flavor='chosen_inline_result')
    print ('Chosen Inline Result:', result_id, from_id, query_string)

MessageLoop(bot, {'inline_query': on_inline_query,
                  'chosen_inline_result': on_chosen_inline_result}).run_as_thread()
print ('Listening ...')

# Keep the program running.
while 1:
    time.sleep(10)

In above code when i send to bot a word (like پروانه) I get this error:

Traceback (most recent call last):
  File "/usr/local/lib/python2.7/dist-packages/telepot/loop.py", line 37, in run_forever
    self._handle(msg)
  File "/usr/local/lib/python2.7/dist-packages/telepot/helper.py", line 1031, in route
    return fn(msg, *args, **kwargs)
  File "bot.py", line 63, in on_inline_query
    bot.answerInlineQuery(query_id, articles, cache_time=5)
  File "/usr/local/lib/python2.7/dist-packages/telepot/__init__.py", line 868, in answerInlineQuery
    return self._api_request('answerInlineQuery', _rectify(p))
  File "/usr/local/lib/python2.7/dist-packages/telepot/__init__.py", line 435, in _api_request
    return api.request((self._token, method, params, files), **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/telepot/api.py", line 137, in request
    return _parse(r)
  File "/usr/local/lib/python2.7/dist-packages/telepot/api.py", line 116, in _parse
    raise exception.BadHTTPResponse(response.status, text, response)
BadHTTPResponse: Status 413 - First 500 characters are shown below:

when i change the line bot.answerInlineQuery(query_id, articles, cache_time=5) to bot.answerInlineQuery(query_id, articles[:-4], cache_time=5) this problem does not appear and the bot sends back data. when i use bot.answerInlineQuery(query_id, articles[:-3], cache_time=5) I get the error again. and when i use bot.answerInlineQuery(query_id, articles[6], cache_time=5) (means exactly the new item of the articles) the exception does not raises. means probably this newly added item does not have any problem. where is wrong? is there any timeout? or is there any limit on the total articles object? all message_text in the items of articles array are less than 4096 characters. I think this a urllib3 limit because when I change my code and try to send articles with 1000 items with only one character as text, I get this error again.