AWS Chatbot strange reply

I'm integrating AWS's Chatbot with Slack. So far, so good, except for requests related to AWS config.

On the Slack integration, I'm getting replies with "NextToken" and what apparently seems to be... a token... :)

However, if I run the equivalent command on AWS Cli, I'm getting the expected result:

$ aws configservice describe-compliance-by-resource
{
    "ComplianceByResources": [
        {
            "ResourceType": "AWS::EC2::Instance",
            "ResourceId": "i-12345678901234567",
            "Compliance": {
                "ComplianceType": "COMPLIANT"
            }
        },
...

Any idea what I'm doing wrong/missing?

Thanks in advance!