Toon Usage

TOON Format Usage Skill

REFERENCE MODE: This skill provides TOON format reference material. Load specific references on-demand based on current task.

Pure reference skill providing TOON (Token-Oriented Object Notation) format specification and usage patterns for agent handoffs and memory persistence.

What This Skill Provides

TOON Specification: Complete technical reference for TOON format syntax, semantics, and conversion patterns.

Agent Patterns: Usage patterns for agent handoffs, memory persistence, and inter-agent data exchange.

Token Efficiency: Guidance on when and how to use TOON for 30-60% token reduction.

Pattern Type

Pattern 10: Reference Library - Pure reference skill with no execution logic. Load references on-demand based on current task.

When to Use This Skill

Activate when:

• Creating agent handoffs - Need TOON format for inter-agent communication
• Designing memory persistence - Need structured data storage in memory layer
• Converting JSON to TOON - Need conversion examples and patterns
• Optimizing token usage - Need token-efficient data representation
• Understanding TOON syntax - Need technical reference for TOON format

Core Concepts

TOON Format Overview

TOON (Token-Oriented Object Notation) is a compact, human-readable encoding of the JSON data model that minimizes tokens.

Key Features:

• 30-60% token reduction vs JSON for uniform arrays
• Declared structure once: Field headers defined upfront, not repeated
• Tabular data: CSV-style rows for uniform arrays
• Explicit clarity: [N] length and {fields} headers improve LLM parsing

Best For:

• Agent handoffs with uniform issue lists
• Coverage reports with tabular data
• Build failures with repeated structure
• Memory persistence with structured session data

NOT For:

• API interchange (use JSON)
• Configuration files (use YAML/JSON)
• Deeply nested structures (>3 levels)
• Non-uniform object shapes

Agent Communication Scope

TOON is ONLY for internal cui-llm-rules marketplace operations:

• Agent-to-agent handoffs
• Memory persistence (memory layer)
• Inter-agent data exchange
• Test fixtures for agent workflows

NOT for:

• Application code or APIs
• General LLM integration
• External data interchange

Available References

Load references progressively based on current task. Never load all references at once.

1. TOON Specification (Technical Reference)

File: knowledge/toon-specification.md

Load When:

• Learning TOON syntax and semantics
• Understanding conversion patterns
• Validating TOON structure
• Comparing with JSON/CSV/YAML

Contents:

• Core syntax (primitives, objects, arrays)
• Uniform arrays (TOON's sweet spot)
• Nested structures and mixing
• Advanced features (optional fields, escaping)
• Conversion examples (Sonar issues, coverage)
• Implementation libraries (TypeScript, Python, Go, Rust, .NET)
• Best practices and optimization tips
• Performance characteristics and trade-offs

Load Command:

Read knowledge/toon-specification.md

2. Agent Patterns (Usage Patterns)

File: knowledge/agent-patterns.md

Load When:

• Creating agent handoff templates
• Designing memory persistence
• Converting JSON fixtures to TOON
• Understanding agent prompt patterns

Contents:

• Handoff template examples (minimal, standard, full)
• Memory persistence patterns
• Agent prompt patterns (receiving/generating TOON)
• Test fixture examples
• Token impact measurements
• Migration guidance

Load Command:

Read knowledge/agent-patterns.md

Usage Workflow

Step 1: Identify Your Goal

Determine what you're trying to accomplish:

• Learning TOON syntax → Load toon-specification.md
• Creating agent handoff → Load agent-patterns.md
• Converting JSON to TOON → Load both references
• Understanding token savings → Load toon-specification.md (performance section)

Step 2: Load Relevant References

Never load all references - Load only what's needed for current task.

Example:

# Creating agent handoff
Read knowledge/agent-patterns.md

# Understanding TOON syntax
Read knowledge/toon-specification.md

Step 3: Apply Patterns

Follow the guidance in loaded references:

• Use TOON for uniform array structures
• Follow tabular data format for repeated objects
• Include [N] length declarations
• Declare {field1,field2} headers explicitly
• Use proper CSV escaping for special characters

Step 4: Validate Syntax

Ensure TOON follows format requirements:

• Length declaration matches row count
• Field count matches header declaration
• CSV escaping for commas in values
• Consistent indentation for nesting

Quick Reference Guide

When to Load What

Learning TOON format:

Read knowledge/toon-specification.md

Creating agent handoffs:

Read knowledge/agent-patterns.md

Converting JSON to TOON:

Read knowledge/toon-specification.md
Read knowledge/agent-patterns.md

TOON Quick Syntax

Uniform Array:

issues[2]{file,line,severity}:
Example.java,42,BLOCKER
Service.java,89,MAJOR

Nested Object:

context:
  task: Fix issues
  files_analyzed: 15

Mixed Structure:

from_agent: quality
to_agent: fix

context:
  task: Fix code quality

issues[2]{file,line,severity}:
A.java,42,HIGH
B.java,89,MEDIUM

Integration with Marketplace

Agent Handoffs

Purpose: Token-efficient data exchange between agents in workflow chains.

Example Workflows:

• Quality → Implement → Test → Verify
• Sonar → Triage → Fix
• Coverage → Analysis → Report

Token Savings: 480 tokens (60%) for 4-agent chain vs JSON.

Memory Persistence

Purpose: Structured session data storage in memory layer.

Use Cases:

• Task history tracking
• Incremental state management
• Multi-session context

Test Fixtures

Purpose: Token-efficient test data for agent workflow tests.

Examples:

• sonar-issues.toon
• coverage-analysis.toon
• build-failure.toon

Key Principles Summary

1. Token Efficiency

TOON provides 30-60% token reduction for uniform arrays vs JSON.

2. Structural Clarity

Explicit [N] and {fields} declarations improve LLM parsing accuracy.

3. Internal Use Only

TOON is for cui-llm-rules marketplace internal operations, not external APIs.

4. Progressive Loading

Load toon-specification.md and agent-patterns.md on-demand, not upfront.

5. Pattern-Driven Usage

Follow established patterns for handoffs, memory, and fixtures.

Quality Verification

Components using this skill should demonstrate:

• TOON used for uniform array structures
• Length declarations [N] match actual row counts
• Field headers {field1,field2} match all rows
• CSV escaping for values with commas
• Proper indentation for nesting
• 30%+ token reduction vs equivalent JSON

Resources

External References

• TOON Specification: https://github.com/toon-format/spec
• TOON Main Repository: https://github.com/toon-format/toon
• TOON Playground: https://toon-format.github.io/playground
• Original Analysis: https://devtoolhub.com/toon-vs-json-token-efficient-ai-format/

Related Skills

• pm-workflow:workflow-patterns - Agent handoff workflow patterns
• plan-marshall:manage-memories - Memory layer operations

Internal References (Load On-Demand)

All references are in knowledge/ directory:

• toon-specification.md - Complete TOON format technical reference
• agent-patterns.md - Agent handoff and memory patterns

Non-Prompting Requirements

This skill is designed to run without user prompts. Required permissions:

File Operations:

• Read(knowledge/**) - Read reference documentation

Ensuring Non-Prompting:

• All file reads use knowledge/ which resolves to skill's mounted path
• Pure reference skill with no writes or executions
• Only the Read tool is used (no prompting scenarios)

This is a Pattern 10 (Reference Library) skill - pure documentation with no execution logic. All content is loaded progressively based on current needs.