Codex Desktop: Markdown preview hides skill descriptions from YAML frontmatter

What version of the Codex App are you using (From “About Codex” dialog)?

26.820.60940 (build 7119), read from the installed macOS app bundle metadata.

What subscription do you have?

Not disclosed; this report concerns the local Markdown preview.

What platform is your computer?

macOS 26.5.2, Apple silicon / arm64.

What issue are you seeing?

When viewing a local SKILL.md in the Codex Desktop Markdown preview, its description is not visible, even though it is present in the source as a valid multiline YAML description: >- field.

This made the skill appear to have no description until the source was inspected. The original file's YAML was parsed locally, and the description value was confirmed to be a nonempty string.

This is a preview/discoverability report, not evidence that the skill loader fails to read the description. It is not yet established whether the behavior is specific to folded YAML scalars or whether the preview hides all frontmatter.

What steps can reproduce the bug?

The reported workflow was:

1. Open a local SKILL.md containing a valid description in YAML frontmatter.
2. Switch to its Markdown preview.
3. Look for the skill description.
4. Compare with the source, where the description is present.

An anonymized equivalent input for reproduction is:

---
name: example-skill
description: >-
  Perform a bounded example task.
  Use this skill when the user requests that task.
---

# Example skill

Follow the task instructions.

The preview behavior was observed by the reporter on the original file. The synthetic example above preserves the relevant structure but has not been independently verified in the UI.

What is the expected behavior?

For a SKILL.md, make the description discoverable in the preview, either by displaying it or by offering an expandable metadata/frontmatter section.

If hiding frontmatter is intentional for general Markdown files, a skill-aware metadata view would resolve the usability issue. No change to valid YAML syntax or skill-loading semantics should be necessary.

Additional information

Related but different reports: #34442 and #34440 describe frontmatter being rendered as ordinary body content. This report concerns a description that is absent from the preview.

No private repository files, paths, credentials, screenshots, logs or conversation transcript are attached.