https://github.com/ansible/ansible/blob/1706d35fc476e36fcced25435c2f1c2401536376/test/lib/ansible_test/_util/controller/sanity/validate-modules/validate_modules/main.py#L414

When a module is in place to provide documentation for an action, it should be allowed to have a doc string.

Without a docstring users of pydocstring will need to suppress:

```
************* Module plugins.modules.git_away
plugins/modules/git_away.py:1:0: C0114: Missing module docstring (missing-module-docstring)
************* Module plugins.modules.git_here
plugins/modules/git_here.py:1:0: C0114: Missing module docstring (missing-module-docstring)
```

With a doc string the module is treated as a "real" module and fails sanity:

```
ansible-module-not-initialized: Execution of the module did not result in initialization of AnsibleModule
```

PEP257 suggests modules should have a docstring, and is generally considered a good practice to inform future developers of the purpose of the file and can be used for documentation generation as well.
msg += " contains terms which are not part of argument_spec: %s" % ", ".join(sorted(set(value).difference(set(spec))))
                self.reporter.error(
                    path=self.object_path,
                    code='required_by-unknown',
                    msg=msg,
                )
    def _validate_argument_spec(self, docs, spec, kwargs, context=None, last_context_spec=None):
        if not self.analyze_arg_spec:
            return
        if docs is None:
            docs = {}
        if context is None:
            context = []
        if last_context_spec is None:
            last_context_spec = kwargs
        try:
            if not context:
                add_fragments(docs, self.object_path, fragment_loader=fragment_loader,
                              is_module=self.plugin_type == 'module')
        except Exception:
            
            return
        
        module = NoArgsAnsibleModule({})
        self._validate_list_of_module_args('mutually_exclusive', last_context_spec.get('mutually_exclusive'), spec, context)
        self._validate_list_of_module_args('required_together', last_context_spec.get('required_together'), spec, context)
        self._validate_list_of_module_args('required_one_of', last_context_spec.get('required_one_of'), spec, context)
        self._validate_required_if(last_context_spec.get('required_if'), spec, context, module)
        self._validate_required_by(last_context_spec.get('required_by'), spec, context)
        provider_args = set()