AI Skill Report Card

Creating Agent Skills

Creates Claude Code agent skill files following documented best practices, including proper structure, frontmatter, and content organization. Use when building new skill modules, packaging expertise into reusable Claude skills, or reviewing existing skills for compliance with best practices.

A-83·Sep 27, 2026·Source: Web
13 / 15

Create a skill file with YAML frontmatter followed by structured markdown:

YAML
--- name: analyzing-spreadsheets description: Analyzes spreadsheet data to extract trends, anomalies, and summary statistics. Use when working with CSV/Excel files or when the user asks for data analysis. ---
Recommendation▾
Example 2 (placeholder task) is weak and somewhat contrived—replace with a second strong domain example showing full skill output
13 / 15

[immediate actionable example]

Recommendation▾
Add a section addressing edge cases like versioning skills, updating existing skills, or handling naming collisions
14 / 15

[step-by-step process]

Recommendation▾
Include a concrete before/after of a poorly-written skill being fixed, to show diagnostic capability not just generation
15 / 20

[input/output pairs]

[guidelines]

[anti-patterns]

14 / 15

Progress:

  • Step 1: Identify the domain expertise or task to package
  • Step 2: Write gerund-form kebab-case name (max 64 chars)
  • Step 3: Write third-person description with trigger phrases (max 1024 chars)
  • Step 4: Draft Quick Start with zero preamble — code/steps only
  • Step 5: Write Workflow as numbered/checklist steps
  • Step 6: Add 2+ concrete Examples (real input → real output)
  • Step 7: Add Best Practices (concise, non-obvious tips)
  • Step 8: Add Common Pitfalls (things to avoid)
  • Step 9: Trim to ~500 lines; split into reference files if longer
  • Step 10: Validate frontmatter syntax and description phrasing
15 / 20

Example 1: Input: "Someone who reviews pull requests for security vulnerabilities in Node.js apps." Output:

YAML
--- name: reviewing-code-security description: Reviews Node.js pull requests for security vulnerabilities such as injection, auth bypass, and unsafe dependencies. Use when reviewing PRs, auditing code, or the user asks for a security review. ---
13 / 15

Run through the checklist against the diff: input validation, auth checks, dependency versions, secrets exposure.

14 / 15

Progress:

  • Scan diff for new/changed endpoints
  • Check input sanitization and parameterized queries
  • Verify auth/authorization on new routes
  • Check for hardcoded secrets or tokens
  • Review new dependencies for known CVEs ...

**Example 2:**
Input: "asdkjhaksjdh"
Output:
```yaml
---
name: handling-placeholder-tasks
description: Provides a minimal placeholder workflow when input is unclear or insufficient. Use when the request lacks enough detail to define real expertise.
---
13 / 15

Ask nothing — treat as a stub. Document assumptions and proceed with a generic best-practice checklist.

14 / 15

Progress:

  • Note that input was insufficient
  • Apply generic best practices for the closest inferable domain
  • Flag for human review
  • Keep the name as a gerund verb phrase describing the action, not the domain noun (writing-tests, not test-writer).
  • Front-load the description with the action, then append "Use when..." triggers — this is what Claude scans to decide relevance.
  • Avoid teaching Claude things it already knows (e.g., "a CSV is comma-separated values"). Only include domain-specific judgment calls.
  • Prefer concrete numbers, thresholds, and defaults over vague guidance ("use temperature 0.2" beats "tune the parameters").
  • If a skill covers multiple large sub-domains, split into a main skill file plus linked reference docs rather than one giant file.
  • Writing descriptions in first or second person ("I help you...", "You can use this to...").
  • Omitting trigger conditions from the description, making it unclear when Claude should invoke the skill.
  • Padding Quick Start with introductory prose instead of jumping straight to action.
  • Making Examples abstract ("input: some data, output: some result") instead of realistic and specific.
  • Letting the skill balloon past ~500 lines instead of modularizing into separate reference files.
0
Grade A-AI Skill Framework
Scorecard
Criteria Breakdown
Quick Start
13/15
Workflow
14/15
Examples
15/20
Completeness
16/20
Format
15/15
Conciseness
14/15