BTW, the page’s parameters (front matter) seems a better place to store those meta (description) than a data file, take the foo category list page as an example.
categories/foo/_index.md
---
title: Foo
description: Describe the Foo category.
---
You’re welcome, it may be helpful that specify a subfolder for those data files, to avoid being conflicted with other data files. For example, data/authors/tarek-oraby.json.
{{ $ptitle := .Title}}
{{ with index .Site.Data.authors (replaceRE `\s` "-" $ptitle | lower)) }}
<p>{{ .description }}</p>
{{ end }}