Custom Agent Usage

Skill Paths

• Workspace skills: .github/skills/
• Global skills: C:/Users/LOQ/.copilot/skills/

Activation Conditions

SHOULD activate when delegation requires:

• Picking a specific custom agent
• Discovering .agent.md files
• Verifying invocability (disable-model-invocation)

SHOULD activate when:

• Discovering available custom agents in workspace
• Understanding .agent.md file structure and frontmatter
• Checking if an agent can be invoked as a subagent
• Learning which agentName to use for delegation
• Understanding agent tools and capabilities

Non-Activation Conditions

Do NOT activate this skill when:

• No custom-agent discovery/selection is needed
• Using purpose-built agents with clear documentation and usage patterns
• Task requires directly implementing solution rather than delegation
• Need to consult documentation about core agents (not custom agents)
• User wants to learn about built-in agents instead of custom ones
• Task is simple enough that delegation would add unnecessary complexity
• Working with agents that don’t follow the .agent.md file structure

Custom Agent Discovery

Custom agents are defined in .agent.md files in:

• System prompts directory: ~/.copilot/agents/ or similar
• Project repository: .copilot/agents/ or .github/copilot/agents/

To discover agents:

1. Search for .agent.md files in the workspace
2. Read frontmatter of each agent file to understand capabilities

Agent Frontmatter

Key frontmatter fields in .agent.md:

Invocability Check

CRITICAL: Only agents with disable-model-invocation: false in frontmatter can be invoked as subagents.

Check frontmatter:

---
name: "Code Explainer"
description: For analyzing and documenting existing code
disable-model-invocation: false  # Must be false for subagent delegation
tools: [Read, Search]
---

Using Custom Agents

Step 1: Discover Available Agents

Search for .agent.md files:

# Find agent files in project
find . -name "*.agent.md"

# Or in workspace directory
.search("*.agent.md")

Step 2: Check Invocability

Verify disable-model-invocation: false is set.

Step 3: Get Agent Name

Use the name field from frontmatter exactly as is.

• If frontmatter has name field value, use that value in quotes
• If name not specified, use filename without .agent.md or .md extension

Step 4: Delegate Task

runSubagent({
  agentName: "Playwright Tester Mode",  // Must match 'name' from frontmatter exactly
  description: "Test checkout flow",
  prompt: "Perform exploratory testing on the checkout flow: product selection → cart → payment confirmation. Generate comprehensive Playwright tests covering success scenarios, validation errors, edge cases (empty cart, payment failures), and accessibility."
})

Workflow Example

// Step 1: Main agent analyzes task and identifies need for testing
// "I need comprehensive testing for the checkout flow"

// Step 2: Discover custom testing agent
// Found: Playwright-Tester.agent.md with disable-model-invocation: false and name: "Playwright Tester Mode"

// Step 3: Delegate to custom agent
runSubagent({
  agentName: "Playwright Tester Mode",
  description: "Test checkout flow",
  prompt: "Perform exploratory testing on the checkout flow: product selection → cart → payment confirmation. Generate comprehensive Playwright tests covering success scenarios, validation errors, edge cases (empty cart, payment failures), and accessibility."
})

// Step 4: Review test output and integrate into test suite

Examples & Scripts

• Agent Discovery Workflow — Examples of finding and using custom agents
• Agent Finder Script — Node.js script to discover and inspect custom agents