implicit ansible file exists remote - ansible

Question

I want to execute tasks only if a file exists on the target.
I can do that, of course, with
- ansible.builtin.stat:
path: <remote_file>
register: remote_file
- name: ...
something:
when: remote_file.stat.exists
but is there something smaller?
You can, for example, check files on the host with
when: '/tmp/file.txt' is file
But that only checks files on host.
Is there also something like that available for files on remotes?
Added, as according the comment section I need to be bit more specific.
I want to run tasks on the target, and on the next run, they shouldn´t be executed again. So I thought to put a file somewhere on the target, and on the next run, when this file exists, the tasks should not be executed anymore.
- name: do big stuff
bigsgtuff:
when: not <file> exists
They should be executed, if the file does not exists.

Answer 1

I am not aware of a way to let the Control Node know during templating or compile time if there exist a specific file on Remote Node(s).
I understand your question that you
... want to execute tasks on the target ...
only if a certain condition is met on the target.
This sounds to be impossible without taking a look on the target before or do a lookup somewhere else, in example in a Configuration Management Database (CMDB).
... is there something smaller?
It will depend on your task, what you try to achieve and how do you like to declare a configuration state.
In example, if you you like to declare the absence of a file, there is no need to check if it exists before. Just make sure it becomes deleted.
---
- hosts: test
become: false
gather_facts: false
tasks:
- name: Remove file
shell:
cmd: "rm /home/{{ ansible_user }}/test.txt"
warn: false
register: result
changed_when: result.rc != 1
failed_when: result.rc != 0 and result.rc != 1
- name: Show result
debug:
msg: "{{ result }}"
As you see, it will be necessary to Defining failure and control how the task behaves. Another example for showing the content.
---
- hosts: test
become: false
gather_facts: false
tasks:
- name: Gather file content
shell:
cmd: "cat /home/{{ ansible_user }}/test.txt"
register: result
changed_when: false
failed_when: result.rc != 0 and result.rc != 1
- name: Show result
debug:
msg: "{{ result.stdout }}"
Please take note, for the given example tasks there are already specific Ansible modules available which do the job better.
According the additional given information in your comments I understand that you like to install or configure "something" and like to leave that fact left on the remote node(s). You like to run the task the next time on the remote node(s) in fact only if it is wasn't successful performed before.
To do so, you may have a look into Ansible facts and Discovering variables: facts and magic variables, especially into Adding custom facts.
What your installation or configuration tasks could do, is leaving a custom .fact file with meaningful keys and values after they were successful running.
During next playbook execution and if gather_facts: true, the information would be gathered from the setup module and you can than let tasks run based on conditions in ansible_local.
Further Q&A
How Ansible gather_facts and sets variables
An introduction to Ansible facts
Loading custom facts
Whereby the host facts can be considered as kind of distributed CMDB, by using facts Cache
fact_caching = yaml
fact_caching_connection = /tmp/ansible/facts_cache
fact_caching_timeout = 129600
you can have the information also available on the Control Node. It might even be possible to organize it in host_vars and group_vars.