landing-page-audit-39

From the files and frontmatter at commit b3bdcd6. This is how much a skill can do, not whether it is risky.

• Installs more skills

  It tells the agent to install other skills, plugins or tool servers.

  SKILL.md:183 (opens in a new tab)

• Runs shell commands

  Its instructions or files give the agent commands to run on your computer.

  SKILL.md:183 (opens in a new tab)

• Names web addresses

  It mentions outside web addresses the agent may visit. We list them but don't follow them.

  Outside links we did not follow

Pattern check: nothing flagged · commit b3bdcd6 · 3 Nov 2026

We checked every text file in this skill, at commit b3bdcd6 on 3 Nov 2026, against 45 published patterns such as download-and-run commands, hidden text and credential access. We don't run the skill, we don't read the web pages it points to, and we can't judge everything its instructions might lead an agent to do. In published tests, pattern checks like this one missed most malicious skills. Read the skill before you install it — especially anything it asks you to download or run.

How the check worksReport an incorrect finding

Each agent reads SKILL.md a little differently. We check the file against each one's published rules; we don't run the skill in any agent.

• Agent Skills specFails

  The open format from agentskills.io, held to the strictest version of each rule among the agents we check.

  • Error

    Line 3: the description value contains a colon followed by a space, which YAML reads as the start of another field. Strict YAML parsers, including the spec's validator, reject the file. F4

    Fix: Put the value in quotes, like this: description: 'CRO analysis for landing pages evaluating headline clarity, CTA placement, trust sign…

  • Note

    There is no license field, so readers can't tell whether they may reuse the skill. O2

    Fix: Add license: with an SPDX name such as MIT or Apache-2.0, or the name of a bundled licence file.

• Claude CodePasses

  Claude Code reads its own extra fields, ignores unknown ones, and still loads a skill whose frontmatter is broken, without its fields.

  • Note

    Line 3: the description value contains a colon followed by a space, which YAML reads as the start of another field. Claude Code quotes the value itself and loads the skill, but other agents reject it. F4

    Fix: Put the value in quotes, like this: description: 'CRO analysis for landing pages evaluating headline clarity, CTA placement, trust sign…

• Claude apps & API uploadFails

  Uploading to claude.ai or the Claude API, or packaging with Anthropic's script, accepts only the six spec fields and stops on anything else.

  • Error

    Line 3: the description value contains a colon followed by a space, which YAML reads as the start of another field. Anthropic's validator rejects it, so packaging and upload fail. F4

    Fix: Put the value in quotes, like this: description: 'CRO analysis for landing pages evaluating headline clarity, CTA placement, trust sign…

  • Note

    The description is 333 characters. The claude.ai Help Center says 200 at most, though Anthropic's API docs and validator allow 1,024. D4

    Fix: If the claude.ai upload refuses it, trim the description to 200 characters.

• OpenAI (Codex & API)Fails

  Codex finds SKILL.md by its exact name and needs a description; OpenAI's Skills API checks the frontmatter against the spec and caps uploads.

  • Error

    Line 3: the description value contains a colon followed by a space, which YAML reads as the start of another field. Codex quotes the value and loads the skill, but OpenAI's upload follows the spec, which needs valid YAML. F4

    Fix: Put the value in quotes, like this: description: 'CRO analysis for landing pages evaluating headline clarity, CTA placement, trust sign…

• VS Code & CopilotPasses with warnings

  VS Code reads skills one folder below .github/skills, .claude/skills or .agents/skills and falls back to the folder name when the name is missing or differs; GitHub's Copilot docs require the exact name SKILL.md.

  • Warning

    Line 3: the description value contains a colon followed by a space, which YAML reads as the start of another field. VS Code's own YAML reader still loads the skill, but may read some values differently. F4

    Fix: Put the value in quotes, like this: description: 'CRO analysis for landing pages evaluating headline clarity, CTA placement, trust sign…

1 file