This package will parse your YAML files in Atom through js-yaml, exposing any issues reported.
$ apm install linter-js-yaml
You can configure linter-js-yaml by editing ~/.atom/config.cson (choose Open Your Config in Atom menu) or in Preferences:
customTags: List of YAML custom tags. (Default: scalar)
Good catch. Let us know what about this package looks wrong to you, and we'll investigate right away.