Skill Creator

Skill Creator

Create new diagnostic skills for the DLM Diagnostics MCP server. Each skill is a self-contained directory with a SKILL.md and supporting reference files.

Prerequisites

• Familiarity with the existing skill structure (see .github/skills/dlm-diagnostics/ as the canonical example).
• Knowledge of the PowerShell cmdlet allowlist in src/powershell/allowlist.ts.
• Understanding of the project's read-only safety model.

Safety Rules

1. Only reference read-only cmdlets — allowed verb prefixes: Get-*, Test-*, Export-*.
2. Never include mutating commands in diagnostic steps — Set-*, New-*, Remove-*, Enable-*, Start-*, Invoke-* must only appear in the "Recommended Actions" output section, clearly marked as manual-review-only.
3. All cmdlets used in the skill must exist in src/powershell/allowlist.ts — if a new Get-* cmdlet is needed, add it to the allowlist as a separate change.
4. No credentials or secrets — never embed tokens, passwords, or connection strings in skill files.

SKILL.md Template

Every skill must have a SKILL.md at its root with the following structure:

---
name: <skill-name>
description: "<One-paragraph description of when to invoke this skill. Include symptom keywords for matching.>"
---

# <Skill Title>

<Brief overview of what this skill investigates.>

## Prerequisites

<Required PowerShell sessions or environment setup.>

## Safety Rules

<Read-only enforcement rules specific to this skill.>

## Decision Tree

| Symptom | Reference |
|---------|-----------|
| <symptom description> | [<filename>.md](references/<filename>.md) |

## Workflow

1. **Identify the symptom** — match user description to the decision tree.
2. **Load the reference file** — read it fully before starting.
3. **Execute diagnostic commands** — step by step using `run_powershell`.
4. **Interpret results** — follow the reference guide's evaluation criteria.
5. **Cross-reference** — load linked references when directed.
6. **Report findings** — summarize using the Output Format below.
7. **Review execution log** — use `get_execution_log` for the audit trail.

## Output Format

<Standard investigation summary template.>

Reference File Structure

Each reference file in references/ should follow this pattern:

# <Issue Title>

## Overview
<Brief description of the issue and when it occurs.>

## Diagnostic Steps

### Step N: <Step Name>
**Command:**
\`\`\`powershell
<Get-* / Test-* / Export-* command>
\`\`\`
**Evaluate:**
- <What to look for in the output>
- <Condition that indicates a problem>

## Root-Cause Table

| Finding | Root Cause | Remediation |
|---------|-----------|-------------|
| <diagnostic finding> | <why it happens> | <fix command or action — marked as manual> |

## Cross-References
- [related-file.md](related-file.md) — <when to follow this link>

Creation Workflow

Follow these steps to create a new skill:

1. Name the skill — use kebab-case (e.g., edr-diagnostics, compliance-search-triage).
2. Write the SKILL.md — follow the template above. Start with the YAML frontmatter name and description.
3. Build the decision tree — list every symptom the skill can diagnose, each mapping to a reference file.
4. Create reference files — one .md per symptom in a references/ subdirectory. Each must include diagnostic steps with exact PowerShell commands, evaluation criteria, a root-cause table, and cross-references.
5. Validate cmdlets — every cmdlet used in diagnostic steps must be in src/powershell/allowlist.ts. If a new read-only cmdlet is needed, add it to the allowlist.
6. Test the flow — mentally walk through at least one symptom end-to-end: decision tree → reference file → commands → evaluation → root cause → remediation.
7. Write the output format — ensure it matches the standard investigation summary template.
8. Mirror the skill — copy the complete skill directory to both locations:
   • .github/skills/<skill-name>/
   • .claude/skills/<skill-name>/
9. Update documentation — if the skill introduces new cmdlets, update CLAUDE.md and .github/copilot-instructions.md.
10. Commit — commit both skill copies and any allowlist changes together.

Validation Checklist

Before finalizing a new skill, verify:

• SKILL.md has valid YAML frontmatter with name and description
• Description includes symptom keywords for AI matching
• Decision tree covers all intended symptoms
• Every decision tree entry links to an existing reference file
• All reference files exist in references/ subdirectory
• All diagnostic commands use only Get-*, Test-*, or Export-* cmdlets
• All cmdlets are present in src/powershell/allowlist.ts
• Mutating commands appear only in remediation sections with manual-review warnings
• Reference files include root-cause tables
• Skill is mirrored in both .github/skills/ and .claude/skills/
• Relative references/ links resolve correctly from both locations

Canonical Example

See .github/skills/dlm-diagnostics/ (or .claude/skills/dlm-diagnostics/) for the reference implementation. It demonstrates all conventions: YAML frontmatter, decision tree, 12 reference files, safety rules, workflow, and output format.