Claude Code Command Patterns

Guide for creating and modifying Claude Code slash commands with proper structure, parallel execution patterns, and agent coordination.

When to Use This Skill

Activate when:

•Creating new Claude Code slash commands
•Modifying existing command structure
•Implementing parallel Task invocations
•Adding TodoWrite progress tracking
•Coordinating multiple agents from commands
•Debugging command-to-agent integration

Command Structure

Required Frontmatter

yaml

---
description: "Command purpose in clear, concise terms"
argument-hint: "[input-type] [optional-params]"
---

Command Body Template

markdown

I am a [command purpose] that [brief description]. My task is to:

1. Setup todo tracking for the workflow
2. Invoke specialized agents using parallel Task calls
3. Read and validate outputs from expected files
4. Create comprehensive report with findings

## Implementation

I will use TodoWrite to track progress, then make parallel Task calls:
- Task with subagent_type: "agent-name-1" - pass the [argument] for [purpose]
- Task with subagent_type: "agent-name-2" - pass the [argument] for [purpose]

Then read outputs, validate them, and create complete report.

Required Elements

1. TodoWrite First

Always setup todo tracking before Task calls:

markdown

I will use TodoWrite to track progress...

2. Parallel Task Calls

Explicitly state parallel execution:

markdown

...then make parallel Task calls:
- Task with subagent_type: "agent-a" - ...
- Task with subagent_type: "agent-b" - ...

3. Argument Passing

Pass meaningful context to each agent:

markdown

- Task with subagent_type: "analyzer" - pass the project_path argument [PATH] for analysis

4. Output Validation

Read and validate actual outputs:

markdown

Then read outputs from [files], validate them, and create complete report.

Execution Patterns

Parallel Execution

When tasks are independent:

markdown

make parallel Task calls:
- Task with subagent_type: "agent-1" - ...
- Task with subagent_type: "agent-2" - ...
- Task with subagent_type: "agent-3" - ...

Sequential Execution

When tasks have dependencies:

markdown

First, use Task with subagent_type: "discovery-agent" to analyze project.
Then, use Task with subagent_type: "plan-agent" with discovery results.
Finally, use Task with subagent_type: "task-agent" with plan output.

Conditional Execution

When execution depends on results:

markdown

First check if [condition] exists using Read tool.
If present, skip to validation phase.
If not, execute discovery workflow.

Argument Extraction Pattern

Commands should document argument extraction for agents:

markdown

## Argument Extraction Instructions

When invoking agents, use explicit argument passing:
- "pass the project_path argument [PATH] for [purpose]"
- "pass the changes-description argument '[DESC]' for [purpose]"

Agents extract these values from their task prompts.

Anti-Patterns to Avoid

Never Use

•Coordinator agents that call other agents (commands coordinate directly)
•Sequential execution when parallel is possible
•Missing TodoWrite progress tracking
•Generic arguments without context
•Assuming outputs without Read/validation
•Incorrect subagent_type references

Incorrect

markdown

# WRONG: Missing TodoWrite
I will invoke agents directly...

# WRONG: No argument passing
- Task with subagent_type: "analyzer"

# WRONG: Sequential when parallel works
First run agent-1, then agent-2, then agent-3...

Correct

markdown

# RIGHT: TodoWrite first
I will use TodoWrite to track progress, then...

# RIGHT: Explicit argument passing
- Task with subagent_type: "analyzer" - pass the project_path argument ./src for code analysis

# RIGHT: Parallel execution
...make parallel Task calls:
- Task with subagent_type: "agent-1" - ...
- Task with subagent_type: "agent-2" - ...

Complete Example

markdown

---
description: "Analyze project security posture and generate comprehensive report"
argument-hint: "[project-path]"
---

I am a security analysis coordinator that evaluates project security across multiple dimensions. My task is to:

1. Setup todo tracking for the security workflow
2. Invoke security agents using parallel Task calls
3. Read and validate outputs from security reports
4. Create comprehensive security assessment

## Implementation

I will use TodoWrite to track progress, then make parallel Task calls:
- Task with subagent_type: "vulnerability-assessment-specialist" - pass the project_path argument for vulnerability scanning
- Task with subagent_type: "security-architecture-analyst" - pass the project_path argument for architecture review
- Task with subagent_type: "security-threat-modeler" - pass the project_path argument for STRIDE analysis

Then read outputs from security reports, validate findings, and create consolidated assessment.

Naming Conventions

•Commands: lowercase-hyphen (e.g., security-review.md)
•Agents: lowercase-hyphen (e.g., security-threat-modeler.md)
•subagent_type: Must match agent filename without .md

Key Principles

•Commands coordinate agents directly (no intermediate coordinators)
•Use TodoWrite for progress tracking
•Prefer parallel execution when tasks are independent
•Pass explicit arguments with clear purposes
•Validate outputs before creating final reports
•Use consistent lowercase-hyphen naming