How does this skill differ from a standard YAML linter?

This skill specifically targets and repairs syntax errors in SKILL.md YAML headers—such as unquoted colons or improper indentation—that often cause automated validation tools to fail during development.

Can I use this skill inside my existing AI code editor?

Yes, it is designed for seamless use within developer environments like CLAUDE_CODE, Cursor, and Windsurf, ensuring your skill files pass validator checks without manual editing.

Will this skill change the actual content or instructions in my SKILL.md file?

No, the skill uses strict extraction logic to isolate the YAML block, ensuring that your skill descriptions, instructions, and rules remain completely untouched during the repair process.

Are there any types of errors that the skill cannot fix?

The fixer uses heuristic-based logic to address common syntax violations; however, it cannot resolve semantic errors or extremely complex, deeply nested YAML structures where user intent is ambiguous.

What exactly is included in the purchase of this skill?

You will receive the full skill logic ready for integration into your AI environment, along with documentation on how to trigger the fix and interpret the change tracking reports.

YAML Frontmatter Fixer

Example session with this skill installed

Fix frontmatter in ./my-skill/SKILL.md

Read your context and instructions
Compiled the yaml frontmatter fixer

Summary: 3 issues found, 3 fixed

1. Unquoted value containing a colon (description)
   before: description: A validator: checks SKILL.md
   after:  description: "A validator: checks SKILL.md"

2. Trailing comma in inline list (tags)
   before: tags: [linter, validator,]
   after:  tags: [linter, validator]

3. Value parsed as a number (name)
   before: name: 1.2-thing
   after:  name: "1.2-thing"

Corrected frontmatter:
---
name: "1.2-thing"
description: "A validator: checks SKILL.md"
tags: [linter, validator]
---

Run skl-validator to verify

Connects securely to your tools. The creator never sees your data.

About this skill

Why does your SKILL.md keep failing to load?

Nine times out of ten it's the frontmatter. An unquoted colon, a trailing comma, a version that looks like a number — YAML is picky, and the error message rarely points at the culprit.

json-frontmatter-fixer reads your frontmatter, finds the common breakages, and repairs them without changing meaning — then shows every fix as a before/after so you can trust it.

What it fixes

Unquoted strings containing a colon (description: A validator: checks...)
Trailing commas in inline lists ([a, b,])
Values that parse as the wrong type (name: 1.2-thing)
Inconsistent list style and stray tabs

What it returns

N issues found, N fixed
A before -> after snippet per fix
The corrected full SKILL.md
A reminder to run skl-validator to confirm

A fast pass over common frontmatter errors. Instruction-only; nothing leaves your machine.

Works with Claude Code, Cursor, Codex CLI, OpenCode, Gemini CLI, WindSurf.

How to use

Skills on Agensi run inside your AI agent. Copy the prompt, paste it into your agent, and it connects to Agensi and installs this skill for you. If a payment is needed, your agent shows it to you first.

Reviews

No reviews yet

Be one of the first to try it. Every listed skill passes our trust checks below.

Security scanned

Passed our 8-point scan before listing

Fresh listing

Recently published to Agensi

Money-back guarantee

Doesn't do what its page promises? You get your money back.

YAML Frontmatter Fixer