skill-creator

name: skill-creator description: Create, validate, or update skills. Triggers on new skill requests, skill audits, extending kit capabilities, or packaging skills. version: 1.0.0

Skill Creator

This skill provides the methodology and standards for building new skills in the Antigravity Marketing Kit. It is the foundational skill — every other skill in this kit should be created or validated using this process.

About Skills in Antigravity

Skills are self-contained instruction packages that give Gemini specialized expertise for specific marketing tasks. Unlike multi-agent systems, skills here serve a single agent. They are context modules: when activated, Gemini reads the SKILL.md and gains procedural knowledge for that domain.

Skills are NOT documentation. They are action-oriented instructions that teach Gemini how to perform tasks, not what concepts mean.

What a skill provides:

1. Trigger conditions — when to activate this skill
2. Domain frameworks — proven methodologies for the task
3. Step-by-step workflows — how to execute common scenarios
4. Scripts — reusable code for deterministic operations
5. References — detailed data too large for SKILL.md
6. Assets — templates and boilerplate for output

Creating a New Skill

Step 1: Define the Scope

Before writing anything, answer these questions:

1. What task does this skill enable? (Specific, not vague)
2. When should Gemini activate this skill? (Trigger phrases, keywords, scenarios)
3. What does the user expect as output? (File type, format, location)
4. Does an existing skill already cover this? (Check .agent/skills/ — consolidate if overlap exists)
5. What reusable resources would help? (Scripts, reference data, templates)

Consolidation rule: Related topics belong in one skill. For example, Google Ads + Meta Ads = ads-management, not two separate skills.

Step 2: Plan the Skill Contents

Analyze concrete use cases and determine what resources to include:

Scripts (scripts/) — For repetitive, deterministic operations that benefit from code rather than natural language instructions. Scripts execute without loading into context, saving tokens.

Examples: data validation, file generation, API calls, batch processing.

References (references/) — For detailed domain knowledge that exceeds SKILL.md's 150-line limit. Loaded on demand when Gemini needs deeper context.

Examples: API schemas, formula tables, research data, checklists.

Assets (assets/) — For templates and boilerplate that Gemini copies and customizes.

Examples: email templates, document scaffolds, configuration files.

Step 3: Initialize the Skill Directory

Create the following structure:

.agent/skills/your-skill-name/
├── SKILL.md
├── scripts/          ← optional
├── references/       ← optional
└── assets/           ← optional

Naming rules for your-skill-name:

• Kebab-case only (lowercase + hyphens)
• Descriptive but concise (max 40 characters)
• Must match the name field in SKILL.md frontmatter exactly

Step 4: Write SKILL.md

Required format:

---
name: your-skill-name
description: Specific trigger conditions. Under 200 characters. Include keywords users would say.
---

# Skill Title

[1-2 sentence purpose statement. What this skill enables.]

## Initial Assessment

Before executing, determine:
1. [Context question relevant to this domain]
2. [Constraint or scope question]
3. [Current state / baseline question]

## Core Methodology

### [Framework or Approach Name]
[Actionable instructions, not theory]

### [Second Framework if applicable]
[Instructions]

## Workflow

### Common Scenario 1: [Name]
1. [Step with specific action]
2. [Step referencing scripts/references if applicable]
3. [Step for output]

### Common Scenario 2: [Name]
1. [Steps]

## Output Specification

- Format: [what file type / structure]
- Location: [where in assets/]
- Naming: [convention]

## Quality Checklist

- [ ] [Domain-specific quality check]
- [ ] [Another check]
- [ ] Brand context loaded from docs/brand-guidelines.md
- [ ] Output saved to assets/ with descriptive filename

Writing style rules:

• Imperative form: "Generate the headline" not "You should generate the headline"
• Verb-first instructions: "To optimize the subject line, apply..." not "The subject line can be optimized by..."
• Concise: no filler words, no restating what Gemini already knows
• Practical: every sentence should change how Gemini acts on a task

Step 5: Write Supporting Resources

For scripts:

• Python or Node.js preferred (cross-platform)
• Include error handling and clear output messages
• Respect .env file hierarchy: process.env > skill/.env > .agent/skills/.env
• Include a requirements.txt or package.json if dependencies exist
• Test manually with real data before committing

For references:

• Each file under 150 lines; split larger docs by logical boundary
• Kebab-case filenames: api-endpoints-auth.md, not APIEndpoints.md
• Include grep patterns in SKILL.md so Gemini knows which reference to load

For assets:

• Use {{placeholder}} syntax for values that vary per user/project
• No hardcoded brand values

Step 6: Validate the Skill

Run through this checklist before considering the skill complete:

Structure:

• SKILL.md exists with valid YAML frontmatter
• name field is kebab-case and matches directory name
• description is under 200 characters with specific trigger words
• SKILL.md is under 150 lines
• Each reference file is under 150 lines
• No information duplicated between SKILL.md and references
• Unused example files deleted

Quality:

• Instructions use imperative form, not second person
• Teaches how to perform tasks, not what concepts mean
• Based on real marketing workflows
• Includes concrete trigger phrases and scenarios
• Cross-references related skills where applicable
• No duplication with existing skills

Scripts (if applicable):

• Cross-platform compatible
• Tested with real inputs
• Dependencies documented
• Error handling present

Step 7: Iterate

After using the skill on real tasks:

1. Note where Gemini struggled or produced suboptimal output
2. Identify missing context, unclear instructions, or wrong frameworks
3. Update SKILL.md or add references to address gaps
4. Re-test and repeat

Skill Pattern Templates

Choose the structure that best fits your skill's purpose:

Workflow-Based — For sequential processes (email campaigns, content creation)

## Overview → ## Workflow Decision Tree → ## Phase 1 → ## Phase 2 → ## Output

Task-Based — For tool collections (SEO has audit, keywords, technical checks)

## Overview → ## Quick Start → ## Task: Audit → ## Task: Keywords → ## Task: Technical

Reference/Guidelines — For standards (brand guidelines, design systems)

## Overview → ## Guidelines → ## Specifications → ## Usage Examples

Framework-Based — For strategy skills (pricing, psychology, competitor analysis)

## Overview → ## Assessment → ## Framework 1 → ## Framework 2 → ## Application

Existing Skills Catalog

Before creating a new skill, verify it doesn't overlap with these existing skills. If overlap exists, extend the existing skill instead.

References

• Validation checklist: references/validation-checklist.md
• Token efficiency guide: references/token-efficiency.md
• Script standards: references/script-standards.md