Ultimate Jekyll meta_description conditional

head.html

{% comment %} TODO this should likely be resolved by proper layout usage (dedicated paginator page layout for starters) {% endcomment %}

{% assign meta_desc = site.description %}
{% unless page.url == '/' %}
  {% if page.meta_description %}
    {% capture meta_desc %}{{ page.meta_description }}{% endcapture %}
  {% elsif page.excerpt %}
    {% capture meta_desc %}{{ page.excerpt | strip_html | strip_newlines | truncate: 160 }}{% endcapture %}
  {% elsif page.content %}
    {% if page.content contains "for post in paginator.posts" %}
      {% capture meta_desc %}{{ paginator.posts | first | strip_html | strip_newlines | strip | split: " - " | first | truncate: 160 }}{% endcapture %}
    {% else %}
      {% capture meta_desc %}{{ page.content | strip_html | strip_newlines | strip | truncate: 160 }}{% endcapture %}
    {% endif %}
  {% endif %}
{% endunless %}
{% endcapture %}
<meta name="description" content="{{ meta_desc }}">