Delegating to CDN Agent

Core Principle

Never handle Fastly CDN operations directly. Always delegate to a specialized sub-agent to keep your context clean and costs low.

Recognition Patterns

Delegate when user says:

• •"query fastly for..."
• •"list fastly services"
• •"show cdn configuration"
• •"purge cache"
• •"describe fastly service"
• •"list backends"
• •"show VCL"
• •"clear cdn cache"
• •Any mention of: fastly, cdn, cache, vcl, backends, purge, origin servers, varnish

ExampleJobInc-Specific Triggers

Also delegate when user mentions these ExampleJobInc domains:

• •"pi.examplejobinc-cdn.com"
• •"images.examplejobinc.com"
• •"hls.examplejobinc.com"
• •"assets.examplejobinc.com"
• •"embed.examplejobinc.com"
• •"crushinator" (image processing backend)

How to Delegate

Use the Task tool with a specialized prompt:

Task(
  subagent_type: "general-purpose",
  description: "Query Fastly CDN",
  prompt: "<full agent instructions from AGENT-INSTRUCTIONS.md>"
)

Agent Prompt Template

When delegating, include:

1. •The complete agent instructions (see AGENT-INSTRUCTIONS.md)
2. •The user's specific request
3. •Clear output format requirements

Example:

You are a Fastly CDN specialist. Your job is to query Fastly using shell wrappers and return clean results.

<AGENT INSTRUCTIONS HERE>

USER REQUEST: List all Fastly services

Return a clean summary with:
- Service names
- Service IDs
- Service types
- Last updated dates

After Agent Returns

1. •Present results cleanly to user
2. •Offer follow-up if relevant (e.g., "Would you like to see backends for pi.examplejobinc-cdn.com?")
3. •Don't expose mechanics (API calls, tokens, CLI commands) to user

Benefits

• •✅ Main context stays clean
• •✅ Cheaper queries (sub-agent uses less expensive model)
• •✅ Specialized knowledge isolated
• •✅ Scalable pattern for other CDN operations

Example Flow

User: "list fastly services"

Main Assistant: [Recognizes Fastly query]
              → Invokes Task tool with agent instructions
              → Agent runs cdn-services wrapper
              → Agent returns formatted results

Main Assistant: "Found 8 Fastly services:

                1. pi.examplejobinc-cdn.com - Image processing CDN
                2. images.examplejobinc.com - Static images
                3. hls.examplejobinc.com - Video streaming
                ...

                Would you like details on any of these?"

Common Query Types

Service Management:

• •"list fastly services"
• •"describe pi.examplejobinc-cdn.com service"
• •"show cdn configuration"

Backend Investigation:

• •"list backends for pi.examplejobinc-cdn.com"
• •"show origin servers"
• •"describe crushinator backend"

VCL Configuration:

• •"list VCL configurations"
• •"show VCL content for version 42"
• •"view custom VCL"

Cache Management:

• •"purge all cache for pi.examplejobinc-cdn.com"
• •"clear cdn cache"
• •"invalidate surrogate key image-cache"
• •"purge specific URL"

Red Flags

DON'T:

• •❌ Try to run fastly-* scripts yourself
• •❌ Attempt Fastly API calls directly
• •❌ Load detailed Fastly CLI knowledge
• •❌ Handle authentication directly
• •❌ Parse complex CDN configurations

DO:

• •✅ Immediately delegate on Fastly keywords
• •✅ Trust the sub-agent's results
• •✅ Present clean summaries to user
• •✅ Suggest relevant follow-up queries
• •✅ Warn about cache purge impact

Cache Purge Safety

When user requests cache purging:

1. •Always delegate to sub-agent (never do yourself)
2. •Confirm service before agent purges
3. •Warn about impact of full cache purges
4. •Prefer specific purges (URL/key) over --all

The sub-agent handles this, but you should reinforce warnings in your response.

ExampleJobInc Infrastructure Context

ExampleJobInc uses Fastly for:

• •Image CDN (pi.examplejobinc-cdn.com) - Crushinator-powered image processing
• •Video CDN (hls.examplejobinc.com) - HLS streaming
• •Static assets (images.examplejobinc.com, assets.examplejobinc.com)
• •Website CDN (www.examplejobinc.com)

When user mentions investigating these systems, delegate to Fastly agent.

Version History

• •1.0.0 (2025-10-15): Initial delegation skill created to reduce context pollution