Posts tagged with "agent-skills"

• Creating AI Coding Agent Skills

  12/29/2025

  Recently Codex was updated to also leverage Agent Skills, established by Anthropic.

  One friction point I have with this blog is creating the Astro frontmatter for the blog posts. I decided this would be a good skill for Codex.

  To create the skill I added a new directory for the skill: .codex/skills/blog-template. Then added these instructions to a SKILL.md file in the directory’s root.

  ---
  name: blog-template
  description: Add or complete Astro Markdown frontmatter for blog posts (title, pubDate, description, tags) by inferring values from the post content. Use when asked to add headers/frontmatter to Markdown in src/content/blog, ensuring only these fields are present and only missing ones are filled.
  ---
  
  # Blog Template
  
  ## Overview
  - Add or complete an Astro frontmatter block for a blog post while leaving the body untouched.
  - Only include `title`, `pubDate`, `description`, and `tags`; ignore other fields.
  - If frontmatter already exists, preserve existing values and only fill missing fields.
  
  ## Workflow
  1. Detect existing frontmatter at the top of the file. Keep provided values for the four allowed fields; drop any other keys from the new block.
  2. Derive field values from the post content:
     - **title**: Prefer the first level-1 heading or the clearest inferred title; use sensible title case and avoid trailing punctuation.
     - **pubDate**: Keep existing value if present; otherwise set to today in `YYYY-MM-DD`.
     - **description**: Write a concise 1–2 sentence summary (often one line is enough). Multi-line is allowed using `|` but keep it brief and accurate.
     - **tags**: Infer key topics/subjects from the post. Rules: lowercase; hyphenate spaces; no punctuation; cap at 6; unique; required even if guessed. Prefer specific nouns over generic filler.
  3. Emit a single frontmatter block at the very top in this form, then the untouched body:
     ```yaml
     ---
     title: |
       Example Title
     pubDate: 2025-12-01
     description: |
       One-sentence summary of the post.
     tags: ['topic-one', 'topic-two']
     ---

  Tag selection hints

  • Choose the main themes, people, places, or technologies mentioned.
  • Skip redundant variants; prefer one canonical form (e.g., ai, not both ai and artificial-intelligence).
  • If content is thin, still provide tags that best match the subject matter.

  
  So far I've been very happy with the results. I often lightly edit what it generates, but it gets me
  close.
  
  A future enhancement is to have Codex first generate a list of existing blog post tags, and then use
  he list as a reference when generating tags for the new post.