Juniper - SNMP not working with prefix list

Question

I have a problem with configuration SNMP on juniper MX2200.

My configuration:

snmp {
    description "Juniper MX2200";
    location "MyHome";
    community tango {
        authorization read-only;
        client-list-name SNMP-list;
    }
    trap-group jun-tr-gr {
        version v2;
        categories {
            chassis;
            link;
        }
    }
}


policy-options {
    prefix-list SNMP-list {
        10.10.20.20/32;
        10.10.10.20/32;
    }
}

When I use snmpwalk as the result I get: Timeout: No Response from 10.0.0.10

In juniper log I have: SNMPD_AUTH_RESTRICTED_ADDRESS: nsa_initial_callback: request from address 10.10.20.20 not allowed

I don't know why this configuration does not work. Can you help me?