Agent Coordination Patterns

Description

Coordination patterns for sequential, parallel, and iterative agent workflows. Defines how agents work together, communicate findings, and maintain context across handoffs in multi-agent systems.

When to Use

Automatically apply this skill when:

• Designing multi-agent workflows
• Coordinating agent handoffs
• Planning agent dependencies
• Integrating agent outputs
• Building complex workflows
• Optimizing agent collaboration

Core Principle: Hybrid Context Sharing

Two complementary layers work together:

1. Transparency Layer (File-Based)

• Human-inspectable files
• Real-time progress visibility
• Easy debugging and inspection
• Clear agent coordination

2. Intelligence Layer (Knowledge Graph)

• Historical learning
• Pattern recognition
• Cross-session persistence
• Audit trails

Agent Integration Protocol

Phase 1: Pre-Execution Context Reading

Before starting work, agents MUST:

1. Read workflow context → Understand overall objective
2. Check agent queue → Know dependencies and position
3. Review shared data → Get requirements and standards
4. Read dependency outputs → Build on previous work

Example Flow:

User delegates to python-developer:

1. Read current-workflow.md → "Building REST API"
2. Read agent-queue.md → "research-assistant completed"
3. Read inter-agent-context.json → "Tech: FastAPI + PostgreSQL"
4. Read research-assistant-output.md → "Requirements defined"
5. Begin implementation with full context

Phase 2: Progress Reporting During Execution

Continuously communicate state:

• Update progress file every 5-10 minutes
• Report current activity clearly
• List completed steps
• Note any blockers immediately
• Estimate remaining time

Phase 3: Post-Execution Output Writing

Produce standardized results:

• Document all accomplishments
• Record technical decisions
• List created artifacts
• Note known issues
• Provide handoff guidance

Coordination Patterns

Sequential Coordination

Agents work one after another, each building on previous work.

Pattern Structure:

Agent A completes → Writes output
  ↓
Agent B reads A's output → Starts work → Writes output
  ↓
Agent C reads A's and B's outputs → Starts work

When to use:

• Clear dependencies exist
• Each step requires previous completion
• Linear workflow progression

Example Workflow:

Research Assistant (30 min)
  ↓ (passes requirements)
Python Developer (90 min)
  ↓ (passes implementation)
Test Architect (45 min)
  ↓ (passes test suite)
Documentation Writer (30 min)

Best Practices:

• Complete handoff notes are critical
• Each agent validates previous work
• Include “next agent needs” section
• Document all assumptions made

Parallel Coordination

Multiple agents work simultaneously on independent tasks.

Pattern Structure:

         ┌→ Agent A → Output A
Start →  ├→ Agent B → Output B  → Integration Agent
         └→ Agent C → Output C

When to use:

• Independent work streams
• No direct dependencies
• Can merge results later
• Want faster completion

Example Workflow:

Requirements Defined
    ├→ Backend Developer (API)
    ├→ Frontend Developer (UI)
    └→ Database Architect (Schema)
         ↓
    Integration Tester (Verify all parts work together)

Best Practices:

• Define clear interfaces upfront
• Use shared contracts (API specs)
• Regular sync points
• Integration agent validates compatibility

Shared Contract Example:

{
  "api_contract": {
    "/api/users": {
      "GET": "returns user list",
      "POST": "creates user"
    }
  },
  "data_models": {
    "User": {
      "id": "string",
      "name": "string",
      "email": "string"
    }
  }
}

Iterative Coordination

Agent revisits work based on feedback from other agents.

Pattern Structure:

Agent A → Agent B (reviews) → Issues found
  ↑                               ↓
  ←───────── Feedback ────────────↓

When to use:

• Quality improvement cycles
• Refinement needed
• Review and feedback loops
• Progressive enhancement

Example Workflow:

Developer → Code Review → Issues Found
    ↑                         ↓
    ←── Fix Issues ──────────↓

Security Auditor → Vulnerabilities Found
    ↑                         ↓
Developer ←── Apply Fixes ───↓

Best Practices:

• Clear feedback format
• Specific actionable items
• Track iteration count
• Define completion criteria

Feedback Format:

## Review Feedback

### Critical Issues (Must Fix)
1. SQL injection vulnerability in `/api/users` line 45
2. Missing authentication on DELETE endpoint

### Improvements (Should Fix)
1. Add input validation for email format
2. Implement rate limiting

### Suggestions (Could Improve)
1. Consider caching for performance
2. Add more descriptive error messages

Hybrid Coordination

Combines multiple patterns for complex workflows.

Example Structure:

Sequential Start:
  Research → Architecture Design
           ↓
Parallel Development:
  ├→ Backend Team
  ├→ Frontend Team
  └→ QA Test Planning
           ↓
Sequential Integration:
  Integration → Testing
           ↓
Iterative Refinement:
  Review ↔ Fixes

When to use:

• Complex projects
• Multiple teams
• Different phases need different patterns
• Optimization opportunities

Coordination Rules

Dependency Management

Hard Dependencies (Must Complete First):

{
  "agent": "test-architect",
  "depends_on": ["python-developer"],
  "reason": "Cannot test code that doesn't exist"
}

Soft Dependencies (Preferred Order):

{
  "agent": "documentation-writer",
  "prefers_after": ["test-architect"],
  "reason": "Better docs with test examples"
}

Communication Protocols

Status Broadcasting:

• STARTING: Beginning work
• IN_PROGRESS: Active work (% complete)
• BLOCKED: Cannot continue
• COMPLETED: Finished successfully
• FAILED: Could not complete

Handoff Requirements:

• Summary of work done
• Decisions made
• Artifacts created
• Known issues
• Next steps guidance

Conflict Resolution

When agents disagree:

1. Document both perspectives
2. Escalate to user if critical
3. Use precedence rules
4. Security > Functionality > Performance

Precedence Rules:

Security Auditor > All Others (security issues)
Architect > Developers (design decisions)
Senior > Junior (experience hierarchy)
Later > Earlier (recent context)

Best Practices

1. Clear Communication

• Explicit handoff notes
• Document all assumptions
• State dependencies clearly
• Update progress frequently

2. Robust Error Handling

• Check for previous failures
• Validate inputs exist
• Handle missing dependencies
• Report blockers immediately

3. Maintain Context

• Read all relevant outputs
• Preserve decision history
• Update shared context
• Avoid duplicating work

4. Quality Gates

• Validate before handoff
• Test integration points
• Review critical paths
• Ensure completeness

Common Pitfalls

• ❌ Starting without reading context
• ❌ Not updating progress during execution
• ❌ Vague or incomplete handoff notes
• ❌ Missing dependency outputs
• ❌ Parallel work without contracts
• ❌ No integration validation
• ❌ Infinite iteration loops

Integration with Other Skills

• agent-file-coordination: Uses file structures for coordination
• multi-agent-workflows: Higher-level workflow orchestration

References

• Related Skills: agent-file-coordination, multi-agent-workflows
• Design Patterns: Sequential, Parallel, Iterative, Hybrid
• Replaces: agent-context-management (coordination sections)