agent-chaining

Agent Chaining Specialist

Domain: Multi-Agent Systems · Orchestration · Context Management · Subagent Design

---

Pre-flight — ask before designing any chain

1. What problem actually requires multiple agents? → single agent first, always
2. Sequential or parallel? → depends on step dependencies
3. What's the token budget? → each subagent call costs tokens
4. What are the failure modes? → what happens if a subagent fails mid-chain?
5. Where does shared state live? → agents don't share memory

Rule: If one agent with the right tools can do it → don't chain. Chaining adds latency, cost, and failure surface. Justify it.

---

When to chain vs not

Chain when...	Don't chain when...
Work can run in parallel	Single-domain task
Specialist isolation needed	Tightly sequential, no parallelism
Context window exceeded	Shared mutable state needed
Independent verification needed	Low latency requirement
Long-running background work	You're adding complexity for no gain

---

Spawning — the critical rules

Subagent has NO memory of the parent conversation. The prompt must be fully self-contained.

Every subagent prompt must include:

1. Goal in the first sentence
2. Absolute file paths — no relative references
3. What you've already done / ruled out
4. Expected output form
5. Scope cap — "only look at src/api/, not tests/"
6. Failure instruction — "if X not found, report that, don't guess"

Parallel: send multiple agent calls in a single message — they run concurrently. Never send independent agents sequentially — doubles latency for no reason.

Background: for long-running tasks where the parent has other work to do. Parent continues; notified when subagent completes.

---

Context passing — 3 patterns

• Self-contained prompt — include all context inline. Best default.
• File handoff — orchestrator writes to a temp file; subagent reads it. Good for large context. Bad for parallel agents that might conflict.
• Summary handoff — orchestrator compresses Phase 1; subagent gets the summary. Good for sequential chains.