Agent Developing Agents

Developing AI Agents

Comprehensive guidance for creating AI agents following repository conventions.

Core Requirements

• Frontmatter: name, description, tools, model, color, skills
• Name must match filename exactly
• Non-empty skills field required

File Operations in .claude/ and .opencode/ Directories

Use the normal Write / Edit tools to create and modify files under .claude/ and .opencode/. Both paths are pre-authorized in .claude/settings.json (Write(.claude/**), Edit(.claude/**), Write(.opencode/**), Edit(.opencode/**)), so no approval prompts fire. Bash heredoc and sed remain appropriate for bulk mechanical substitutions across many files, but there is no restriction on direct edits.

This applies to:

• .claude/agents/*.md — agent definitions
• .claude/skills/*/SKILL.md — skill files (source of truth for both Claude Code AND OpenCode; OpenCode reads natively per opencode.ai/docs/skills, no mirror)
• .claude/skills/*/reference/*.md — skill reference modules
• .opencode/agents/*.md — OpenCode agent mirrors

After editing .claude/agents/ sources, run npm run generate:bindings so the .opencode/agents/ mirror stays aligned. The pre-commit hook validates both formats. Skills under .claude/skills/ are not mirrored — restart any active OpenCode session to pick up edits.

References

AI Agents Convention

Tool Usage Documentation

Agents should document which tools they use and why, helping users understand capabilities and maintainers understand dependencies.

Tool Documentation Pattern

Add "Tools Usage" section (optional but recommended) listing each tool with its purpose:

## Tools Usage

- **Read**: Read files to validate/create/fix
- **Glob**: Find files by pattern in directories
- **Grep**: Extract content patterns (code blocks, commands, etc.)
- **Write**: Create/update files and reports
- **Bash**: Generate UUIDs, timestamps, file operations
- **Edit**: Apply fixes to existing files
- **WebFetch**: Access official documentation URLs
- **WebSearch**: Find authoritative sources, verify claims

When to Document Tools

Recommended for:

• Agents with 4+ tools (helps users understand capabilities)
• Agents where tool selection isn't obvious
• Agents with unusual tool combinations
• Reference documentation for complex agents

Optional for:

• Simple agents with 2-3 obvious tools
• Agents following standard patterns

Tool Documentation Examples

Checker Agents (Read, Glob, Grep, Write, Bash, WebFetch, WebSearch):

## Tools Usage

- **Read**: Read documentation files to validate
- **Glob**: Find markdown files in directories
- **Grep**: Extract code blocks, commands, version numbers
- **Write**: Generate audit reports to generated-reports/
- **Bash**: Generate UUIDs, timestamps for reports
- **WebFetch**: Access official documentation URLs
- **WebSearch**: Find versions, verify tools, fallback for 403s

Fixer Agents (Read, Edit, Bash, Write):

## Tools Usage

- **Read**: Read audit reports and files to fix
- **Edit**: Apply fixes to docs/, repo-governance/, `.claude/`, and `.opencode/` files
- **Bash**: Run shell commands, bulk sed substitutions across many files, timestamp/UUID generation
- **Write**: Generate fix reports to generated-reports/

Maker Agents (Read, Write, Glob, Grep, Bash):

## Tools Usage

- **Read**: Read existing files for context
- **Write**: Create new documentation, agent, and skill files (including under `.claude/` and `.opencode/`)
- **Glob**: Find related files for cross-references
- **Grep**: Extract patterns for consistency
- **Bash**: Run shell commands, bulk text substitutions, directory creation

Placement

Add "Tools Usage" section:

• After "Core Responsibility" or main description
• Before detailed workflow sections
• Near top for quick reference

When to Use This Agent

Agents should include guidance on when to use them vs other agents, improving discoverability and preventing misuse.

When to Use Pattern

Add "When to Use This Agent" section with two subsections:

## When to Use This Agent

**Use when**:

- [Primary use case 1]
- [Primary use case 2]
- [Primary use case 3]
- [Specific scenario that fits]

**Do NOT use for**:

- [Anti-pattern 1] (use [other-agent] instead)
- [Anti-pattern 2] (use [alternative-tool/approach])
- [Edge case that doesn't fit]
- [Common misuse scenario]

When to Include

Highly Recommended for:

• Agents with overlapping scopes (e.g., multiple checkers)
• Agents that users might confuse (e.g., maker vs editor)
• Agents with specific prerequisites (e.g., needs audit report)
• Specialized agents with narrow focus

Examples by Agent Type:

Checker Agents:

## When to Use This Agent

**Use when**:

- Validating [domain] content before release
- Checking [domain] after updates
- Reviewing community contributions
- Auditing [domain] for compliance

**Do NOT use for**:

- Link checking (use [link-checker] instead)
- File naming/structure (use [rules-checker])
- Creating new content (use [maker-agent])
- Fixing issues (use [fixer-agent] after review)

Fixer Agents:

## When to Use This Agent

**Use when**:

- After running [checker-agent] - You have an audit report
- Issues found and reviewed - You've reviewed checker's findings
- Automated fixing needed - You want validated issues fixed
- Safety is critical - You need re-validation before changes

**Do NOT use for**:

- Initial validation (use [checker-agent])
- Content creation (use [maker-agent])
- Manual fixes (use Edit tool directly)
- When no audit report exists

Maker Agents:

## When to Use This Agent

**Use when**:

- Creating new [domain] content
- Need standardized structure/format
- Following [domain] conventions
- Building content from templates

**Do NOT use for**:

- Validating existing content (use [checker-agent])
- Fixing issues (use [fixer-agent])
- Bulk updates (use Edit tool for simple changes)
- Content outside [domain] scope

Placement

Add "When to Use This Agent" section:

• After agent description or core responsibility
• Before detailed workflow/process sections
• Early in file for quick reference

Benefits

✅ Improves agent discoverability ✅ Prevents misuse and confusion ✅ Clarifies agent boundaries ✅ Guides users to appropriate alternatives ✅ Reduces trial-and-error

Updated References

AI Agents Convention - Complete specification Agent Documenting References Skill Agent Selecting Models Skill

Documenting Agent References

Standard structure for "Reference Documentation" sections in agent files to ensure consistent navigation and discoverability.

When This Skill Loads

This Skill auto-loads when implementing agents or updating agent documentation sections.

Reference Documentation Section

All agents SHOULD include a "Reference Documentation" section near the end (before any appendices) with standardized subsections.

Section Template

## Reference Documentation

**Project Guidance**:

- [AGENTS.md](../../../CLAUDE.md) - Primary guidance for OpenCode
- [Agent-specific convention](path/to/convention.md) - Domain-specific standards

**Related Agents**:

- `maker-agent` - Creates content for this domain
- `checker-agent` - Validates content (upstream dependency)
- `fixer-agent` - Fixes issues found by checker
- `related-domain-agent` - Related functionality

**Related Conventions**:

- [Primary Convention](path/to/convention.md) - Main standards this agent implements
- [Secondary Convention](path/to/convention.md) - Additional relevant standards

**Skills**:

- `primary-skill` - Main Skill for domain knowledge
- `wow-assessing-criticality-confidence` - Criticality assessment (if applicable)
- `wow-generating-validation-reports` - Report generation (if applicable)

Subsection Details

Project Guidance

Purpose: Link to primary project instructions and domain-specific conventions.

Always Include:

• AGENTS.md.*primary guidance for all agents)

Conditionally Include:

• Domain-specific conventions (e.g., README Quality Convention for readme-agents)
• Framework-specific guidance (e.g., Next.js guide for ayokoding-web-agents)
• Special standards relevant to agent's scope

Pattern:

**Project Guidance**:

- [AGENTS.md](../../../CLAUDE.md) - Primary guidance
- [Specific Convention](path/to/convention.md) - Domain standards

Related Agents

Purpose: Help users understand agent ecosystem and workflow relationships.

Include:

• Upstream agents: Agents this agent depends on (e.g., checker for fixer)
• Downstream agents: Agents that depend on this one (e.g., fixer for checker)
• Parallel agents: Agents in same family/domain (e.g., other checkers)
• Complementary agents: Agents with related functionality

Organize by Relationship:

**Related Agents**:

- `upstream-agent` - Description of relationship
- `downstream-agent` - Description of relationship
- `parallel-agent` - Description of functionality

Examples by Agent Type:

Maker Agents:

- `checker-agent` - Validates content created by this maker
- `related-maker` - Creates content in related domain

Checker Agents:

- `maker-agent` - Creates content this checker validates
- `fixer-agent` - Fixes issues found by this checker
- `related-checker` - Validates related aspects

Fixer Agents:

- `checker-agent` - Generates audit reports this fixer processes
- `maker-agent` - Updates content after fixes applied

Related Conventions

Purpose: Link to conventions and development practices the agent implements.

Include:

• Primary convention agent implements
• Secondary conventions relevant to agent's scope
• Development practices agent follows (e.g., AI Agents Convention)
• Standards agent enforces (for checkers)

Pattern:

**Related Conventions**:

- [Primary Convention](path/to/convention.md) - Main standards
- [Secondary Convention](path/to/convention.md) - Additional standards
- [Development Practice](path/to/practice.md) - Implementation guidance

Checkers Should List:

• Conventions they validate against
• Quality standards they enforce

Makers Should List:

• Conventions they follow when creating content
• Formatting standards they apply

Skills

Purpose: Reference Skills the agent uses for domain knowledge and patterns.

Include:

• All Skills listed in agent's skills: frontmatter field
• Skills should be listed without path (just skill name)
• Brief description of what each Skill provides

Pattern:

**Skills**:

- `domain-skill` - Domain-specific knowledge
- `wow-skill` - Cross-cutting pattern or workflow
- `agent-skill` - Agent development guidance

Note: Skills section duplicates frontmatter skills: field for documentation visibility.

Placement in Agent Files

Recommended Location: Near end of agent file, before any appendices or examples.

Typical Structure:

# Agent Name

## Agent Metadata

- **Role**: [Maker (blue) / Checker (green) / Fixer (yellow) / Implementor (purple)]

[Agent description]

## Core Responsibility

[What agent does]

## Main Content Sections

[Detailed agent instructions]

## Reference Documentation

[Reference sections using template above]

## Appendices (Optional)

[Additional examples, edge cases, etc.]

Examples by Agent Family

docs-family Agents

## Reference Documentation

**Project Guidance**:

- [AGENTS.md](../../../CLAUDE.md) - Primary guidance
- [Content Quality Principles](../../../repo-governance/conventions/writing/quality.md)
- [Diátaxis Framework](../../../repo-governance/conventions/structure/diataxis-framework.md)

**Related Agents**:

- `docs-maker` - Creates documentation
- `docs-checker` - Validates documentation
- `docs-fixer` - Fixes documentation issues
- `docs-tutorial-checker` - Specialized tutorial validation

**Related Conventions**:

- [Content Quality Principles](../../../repo-governance/conventions/writing/quality.md)
- [Factual Validation Convention](../../../repo-governance/conventions/writing/factual-validation.md)
- [Linking Convention](../../../repo-governance/conventions/formatting/linking.md)

**Skills**:

- `docs-applying-content-quality` - Content quality standards
- `docs-validating-factual-accuracy` - Fact-checking methodology
- `wow-assessing-criticality-confidence` - Criticality assessment
- `wow-generating-validation-reports` - Report generation

readme-family Agents

## Reference Documentation

**Project Guidance**:

- [AGENTS.md](../../../CLAUDE.md) - Primary guidance
- [README Quality Convention](../../../repo-governance/conventions/writing/readme-quality.md)

**Related Agents**:

- `readme-maker` - Creates README content
- `readme-checker` - Validates README quality
- `readme-fixer` - Fixes README issues
- `docs-checker` - Validates other documentation

**Related Conventions**:

- [README Quality Convention](../../../repo-governance/conventions/writing/readme-quality.md)
- [Content Quality Principles](../../../repo-governance/conventions/writing/quality.md)

**Skills**:

- `readme-writing-readme-files` - README-specific standards
- `wow-assessing-criticality-confidence` - Criticality assessment
- `wow-generating-validation-reports` - Report generation

plan-family Agents

## Reference Documentation

**Project Guidance**:

- [AGENTS.md](../../../CLAUDE.md) - Primary guidance
- [Plans Organization Convention](../../../repo-governance/conventions/structure/plans.md)

**Related Agents**:

- `plan-maker` - Creates project plans
- `plan-checker` - Validates plan quality
- [plan-execution workflow](../../../repo-governance/workflows/plan/plan-execution.md) - Execute plans (calling context orchestrates; no dedicated subagent)
- `plan-execution-checker` - Validates completed work
- `plan-fixer` - Fixes plan issues

**Related Conventions**:

- [Plans Organization Convention](../../../repo-governance/conventions/structure/plans.md)
- [Gherkin Acceptance Criteria](../../../repo-governance/development/infra/acceptance-criteria.md)

**Skills**:

- `plan-creating-project-plans` - Plan structure and organization
- `plan-writing-gherkin-criteria` - Acceptance criteria patterns
- `wow-assessing-criticality-confidence` - Criticality assessment

Benefits of Standardization

✅ Improved Discoverability: Users can quickly find related agents and conventions
✅ Consistent Navigation: Same structure across all agents
✅ Clear Relationships: Understand agent dependencies and workflows
✅ Better Maintainability: Easy to update references across agents
✅ Enhanced Documentation: Skills and conventions properly referenced

Best Practices

1. Keep Links Current: Update when conventions move or rename
2. Be Selective: Only include truly relevant references
3. Describe Relationships: Explain how related agents connect
4. Match Frontmatter: Ensure Skills section matches skills: field
5. Use Relative Paths: Make links work from agent file location
6. Group Logically: Keep subsections organized and scannable

Key Takeaways

• Standard structure: Use consistent subsections across all agents
• Four subsections: Project Guidance, Related Agents, Related Conventions, Skills
• Clear relationships: Help users understand agent ecosystem
• Proper placement: Near end of agent file before appendices
• Keep current: Update references when files move or change
• Match frontmatter: Skills section mirrors skills: field

This standardization improves agent documentation consistency and helps users navigate the agent ecosystem effectively.

Selecting AI Models for Agents

Guidelines for choosing between sonnet and haiku models based on agent capabilities and task requirements.

When This Skill Loads

This Skill auto-loads when implementing agents or documenting model selection rationale.

Available Models

Sonnet (claude-sonnet-4-5)

Characteristics:

• Advanced reasoning capabilities
• Complex decision-making
• Deep pattern recognition
• Sophisticated analysis
• Multi-step orchestration
• Higher cost, slower performance

Use for: Complex, reasoning-intensive tasks

Haiku (claude-haiku-3-5)

Characteristics:

• Fast execution
• Straightforward tasks
• Pattern matching
• Simple decision-making
• Cost-effective
• Lower cost, faster performance

Use for: Simple, well-defined tasks

Decision Framework

Use Sonnet When Task Requires

✅ Advanced Reasoning

• Analyzing technical claims for subtle contradictions
• Distinguishing objective errors from subjective improvements
• Detecting false positives in validation findings
• Context-dependent decision-making
• Inferring user intent from ambiguous requests

✅ Complex Pattern Recognition

• Cross-referencing multiple documentation files
• Identifying conceptual duplications (not just verbatim)
• Detecting inconsistencies across architectural layers
• Understanding domain-specific patterns
• Recognizing semantic similarities

✅ Sophisticated Analysis

• Verifying factual accuracy against authoritative sources
• Assessing confidence levels (HIGH/MEDIUM/FALSE_POSITIVE)
• Evaluating code quality and architectural decisions
• Analyzing narrative flow and pedagogical structure
• Determining fix safety and impact

✅ Multi-Step Orchestration

• Coordinating complex validation workflows
• Managing dependencies between validation steps
• Iterative refinement processes
• Dynamic workflow adaptation
• Error recovery and retry logic

✅ Deep Web Research

• Finding and evaluating authoritative sources
• Comparing claims against official documentation
• Version verification across multiple registries
• API correctness validation
• Detecting outdated information

Use Haiku When Task Is

✅ Pattern Matching

• Extracting URLs from markdown files
• Finding code blocks by language
• Matching file naming patterns
• Regular expression searches
• Simple syntax validation

✅ Sequential Execution

• File existence checks
• URL accessibility validation
• Cache file reading/writing
• Date comparisons
• Status reporting

✅ Straightforward Validation

• Checking if files exist
• Verifying link format (contains .md)
• Counting lines or characters
• Comparing timestamps
• Simple YAML/JSON parsing

✅ No Complex Reasoning

• Tasks with clear pass/fail criteria
• No ambiguity or judgment required
• Deterministic outcomes
• No context analysis needed
• No trade-off decisions

✅ High-Volume Processing

• Checking hundreds of links
• Validating many files
• Batch operations
• Performance-critical tasks
• Cost-sensitive operations

Model Selection Matrix

Agent-Specific Examples

Sonnet Examples

docs-checker (Complex validation):

model: sonnet

Reasoning:

• Analyzes technical claims for contradictions
• Deep web research for fact verification
• Pattern recognition across multiple files
• Complex decision-making for criticality levels
• Multi-step validation orchestration

docs-fixer (Sophisticated analysis):

model: sonnet

Reasoning:

• Re-validates findings to detect false positives
• Distinguishes objective errors from subjective improvements
• Assesses confidence levels (HIGH/MEDIUM/FALSE_POSITIVE)
• Complex decision-making for fix safety
• Trust model analysis (when to trust checker)

docs-tutorial-checker (Pedagogical analysis):

model: sonnet

Reasoning:

• Evaluates narrative flow and learning progression
• Assesses hands-on element quality
• Analyzes visual completeness
• Determines tutorial type compliance
• Sophisticated quality judgment

Haiku Examples

docs-link-checker (Straightforward validation):

model: haiku

Reasoning:

• Pattern matching to extract URLs
• Sequential URL validation via requests
• File existence checks for internal references
• Cache management (read/write YAML, compare dates)
• Simple status reporting (working/broken/redirected)
• No complex reasoning required

docs-file-manager (File operations):

model: haiku

Reasoning:

• Straightforward file operations (move, rename, delete)
• Simple path manipulation
• Git history preservation (scripted commands)
• No complex decision-making
• Deterministic outcomes

Documenting Model Selection

Model Selection Justification Pattern

Include in agent documentation to explain model choice:

For Sonnet Agents:

**Model Selection Justification**: This agent uses `model: sonnet` because it requires:

- [Reasoning capability 1 - e.g., "Advanced reasoning to analyze technical claims"]
- [Reasoning capability 2 - e.g., "Deep web research to verify facts"]
- [Reasoning capability 3 - e.g., "Pattern recognition across multiple files"]
- [Decision-making type - e.g., "Complex decision-making for criticality levels"]
- [Orchestration need - e.g., "Multi-step validation workflow orchestration"]

For Haiku Agents:

**Model Selection Justification**: This agent uses `model: haiku` because it performs straightforward tasks:

- [Simple task 1 - e.g., "Pattern matching to extract URLs"]
- [Simple task 2 - e.g., "Sequential URL validation via web requests"]
- [Simple task 3 - e.g., "File existence checks"]
- [Simple task 4 - e.g., "Cache management (read/write/compare)"]
- [Simple task 5 - e.g., "Simple status reporting"]
- No complex reasoning or content generation required

Placement in Agent Files

Add justification near the top of agent file, after agent description:

---
name: example-agent
description: Agent description here
model: sonnet
---

# Agent Name

## Agent Metadata

- **Role**: [Role description]

**Model Selection Justification**: [justification here]

[Rest of agent documentation]

Cost and Performance Considerations

Sonnet Trade-offs

Costs:

• Higher per-token cost (~10x haiku)
• Slower response time
• More resource-intensive

Benefits:

• Higher quality reasoning
• Better context understanding
• More accurate decisions
• Handles ambiguity well

Use when: Quality and accuracy more important than cost/speed

Haiku Trade-offs

Benefits:

• Lower per-token cost (~10x cheaper)
• Faster response time
• Efficient for high-volume tasks

Limitations:

• Less sophisticated reasoning
• May struggle with ambiguity
• Better for deterministic tasks

Use when: Cost and speed more important than complex reasoning

Decision Checklist

Before selecting a model, ask:

1. Does the task require judgment calls?

   • Yes → Sonnet
   • No → Haiku

2. Are there multiple valid interpretations?

   • Yes → Sonnet
   • No → Haiku

3. Does it need deep analysis of context?

   • Yes → Sonnet
   • No → Haiku

4. Will it make complex decisions?

   • Yes → Sonnet
   • No → Haiku

5. Is it high-volume, low-complexity?

   • Yes → Haiku
   • No → Sonnet

6. Does cost matter more than quality?

   • Yes → Haiku
   • No → Sonnet

Common Mistakes

❌ Using Sonnet for Simple Tasks:

# Overkill - use haiku
model: sonnet # Just checking if files exist

❌ Using Haiku for Complex Analysis:

# Insufficient - use sonnet
model: haiku # Analyzing code quality and architecture

✅ Match Model to Task Complexity:

# Simple pattern matching
model: haiku

# Complex reasoning
model: sonnet

Key Takeaways

• Sonnet = Complex reasoning, sophisticated analysis, multi-step orchestration
• Haiku = Simple tasks, pattern matching, straightforward validation
• Document rationale = Include model selection justification in agent files
• Consider trade-offs = Balance cost/speed vs quality/capability
• Match complexity = Use appropriate model for task requirements
• When in doubt = Choose sonnet for quality, haiku for speed/cost

Proper model selection ensures optimal performance, cost-effectiveness, and task completion quality.

Source: wahidyankf/ose-public — distributed by TomeVault.