create-skill

Creating a Codex skill involves capturing user intent, drafting a SKILL.md file with YAML frontmatter for metadata, bundling optional scripts or references, and iterating through trigger-evaluation loops until the skill description is stable and reliably triggers.

A trigger-eval loop is an iterative process that executes skill trigger evaluations, collects structured results into evals.json, and analyzes benchmark data to refine the skill's triggering description for better discovery and reliable activation within Codex.

Yes, pyyaml is a required dependency for this skill creation workflow. You need the pyyaml package installed in your environment to properly parse, generate, and manage the YAML frontmatter embedded in the SKILL.md files.

Optimizing a skill description uses a built-in improve-description flow that analyzes evaluation results and iteratively refines the YAML frontmatter description field, ensuring the skill triggers correctly and is easily discovered by the Codex system.

Yes, you can organize and bundle optional resources including scripts, references, and assets alongside the SKILL.md file. These components are structured for on-demand use by Codex when the skill is triggered during execution.

The best approach is structuring SKILL.md with YAML frontmatter containing the skill name, description, and compatibility metadata, followed by a Markdown body with compelling operational instructions that guide the automation behavior clearly.