[mattapperson]

Summary

Adds .github/workflows/validate-skills.yml. It runs gh skill publish --dry-run . on every PR and on every push to main. This is the first CI in the repo.

Why: #192 merged a description with an unquoted : . After that, gh skill install OpenRouterTeam/skills openrouter-decisions failed with invalid frontmatter YAML: yaml: line 2: mapping values are not allowed in this context. publish --dry-run uses the same frontmatter parser as install, plus the agentskills.io checks: name and description are present, and name matches the directory. So the check fails on exactly the errors users hit at install time. Warnings such as a missing license or a long body don't fail it.

• The gh CLI is pinned to 2.103.3 and downloaded from the cli/cli release, because gh skill is a preview command and may not exist on the runner's gh.
• No token is needed. I ran the dry run locally with no gh auth and it passed.

Verified:

• Against main before Added double quotes around the description #198, the first CI run failed with error openrouter-decisions invalid frontmatter YAML ....
• After merging main with Added double quotes around the description #198, the check passes in CI and locally.
• actionlint passes.

What still doesn't work

• It covers only the frontmatter half of chore: add CI — lint SKILL.md frontmatter and smoke-test all scripts #20. The script smoke tests aren't included.

Searched existing PRs: #193 adds the third-party LintLang linter. I ran its exact command (lintlang scan --discover . --fail-on fail, 0.8.1) on the broken main, and it passed all 19 SKILL.md files, including openrouter-decisions, so it doesn't catch this class of error. This PR doesn't supersede #193.

Link to Devin session: https://openrouter.devinenterprise.com/sessions/485ff7dc41114055a8d0407a0b3f7911
Open in Devin Desktop: https://openrouter.devinenterprise.com/desktop/session/485ff7dc41114055a8d0407a0b3f7911?variant=devin
Requested by: @mattapperson

---

[devin-ai-integration]

I'll fix CI failures and address comments from users with write access that start with 'Devin'.

• Disable automatic comment, CI, and merge conflict monitoring

---

Original prompt from Matt

SYSTEM:
<latest_message>
Matt Apperson (U096UCX4GDS) [ts=1793121284.635609]: @Devin installing skills from our skills repo is resulting in an error of "failed to install skill "openrouter-decisions": could not inject metadata: invalid frontmatter YAML: yaml: line 2: mapping values are not allowed in this context" look into this
</latest_message>

=== BEGIN THREAD HISTORY (in #eng-devex-team) ===
Matt Apperson (U096UCX4GDS) [ts=1793121284.635609]: @Devin installing skills from our skills repo is resulting in an error of "failed to install skill "openrouter-decisions": could not inject metadata: invalid frontmatter YAML: yaml: line 2: mapping values are not allowed in this context" look into this
=== END THREAD HISTORY ===
Channel ID: C0BCDN7RHJM
Thread URL: https://openrouter.slack.com/archives/C0BCDN7RHJM/p1793121284635609?thread_ts=1793121284.635609&amp;cid=C0BCDN7RHJM

The <latest_message> is the message that you should use to guide your goals + task for this session, and you should use the rest of the slack thread as context.
A [ts=...] marker on a Slack message is that message's timestamp. To act on a specific message with the slack tool (e.g. adding an emoji reaction via the reaction command), pass that value as timestamp along with the Channel ID — no extra lookup call is needed.

[devin-ai-integration]

✅ Devin Review: No Issues Found

Devin Review analyzed this PR and found no bugs or issues to report.

[devin-ai-integration]

Thanks, Perry. I've applied both inline items in 0067915 and already removed the stale #198 caveat from the PR body. Making validate a required status check in the basic ruleset needs repo admin, so I've raised it with the requester rather than changing it here.

[perry-the-pr-maintainer]

Perry's Review

Verdict: ✅ LGTM

Both findings from my previous review are fixed in 00679152, and I verified the fixes rather than reading them:

• The actions/checkout step — pinned to 11d5960a326750d5838078e36cf38b85af677262, which is the commit the v4 tag resolves to.
• The "Install pinned GitHub CLI" step — the tarball is downloaded, its published checksum verified, and only then extracted. I ran the step in a clean RUNNER_TEMP: it installs gh 2.103.3 and exits 0. I then tampered the tarball and re-ran it: FAILED … 1 computed checksum did NOT match, exit 1. I also checked the case where grep matches nothing — sha256sum: 'no properly formatted checksum lines found', exit 1 — so a renamed or missing asset fails closed rather than checking nothing.

The check still does its job on the current head: gh skill publish --dry-run . exits 0 on this tree, and exits 1 with invalid frontmatter YAML: yaml: line 2: mapping values are not allowed in this context when the pre-#198 unquoted description is restored. It also catches a newly added skill with broken YAML, a skill with no frontmatter, and a name/directory mismatch, and it correctly ignores the license/long-body warnings. The stale "will fail until #198 merges" caveat is gone from the description.

One thing this PR does not do, which is worth stating plainly so nobody reads more safety into it than exists: the check is not yet required to merge. The active basic ruleset (14604602) contains only deletion, non_fast_forward, and pull_request rules — there is no required_status_checks rule. A red run here is visible on the PR but does not block the merge, so recurrence is still possible. Adding "Validate skills" under Settings → Rules → basic → required status checks closes it. I am approving the workflow because that is a repository-settings change outside this diff, not a defect in it — but please make that change, or this is a signal rather than a gate.

Risk assessment

Risk: 🟡 Medium

Dimension	Severity	Risk	Reasoning
Implementation risk	🟩	Low	Install, checksum, tamper-detection, and the validation step were all executed and behave correctly.
Premise risk	🟨🟨	Medium	The check catches the regression, but as merged it reports rather than blocks until it is made required.
Estimated impact	🟨🟨	Medium	Worst case a broken skill frontmatter ships again and users hit the same install error.

Risk Factor	Severity	Risk	Reasoning
Reversibility	🟩	Low	A workflow file reverts cleanly.
Detectability	🟩	Low	The failure is printed on every affected PR.
Blast radius	🟩	Low	Repo CI only; no runtime surface.
Data integrity		None	No persisted state.
Financial exposure		None	No billing surface.
Security and privacy exposure	🟩	Low	Download is now checksum-verified and the action is commit-pinned.
Propagation	🟨🟨	Medium	A bad skill still reaches users via gh skill install and the plugin marketplace if merged past a red run.
Availability	🟩	Low	A failed download fails one job, not a product path.
Recovery cost	🟩	Low	One-line quoting fix, as #198 showed.
Time to correct	🟩	Low	Immediate once noticed.

Estimated impact: Worst case is a repeat of #192 — malformed skill frontmatter reaches main and every user installing that skill gets an error that looks like a CLI fault rather than a repo defect.