check-if-disk yaml code

[ansible@control lesson9]$ cat jw.yaml
---
- name: Check disks
  hosts: all
  tasks:
    - shell: lsblk
      register: block_listing
    - debug:
        msg: echo "You have a second disk"
      #when: '"sdb" in ansible_facts.devices'
      #when: ansible_facts.devices.sdb is defined or ansible_facts.devices.vdb is defined
      when: '"sdb" in block_listing.stdout'