Subagents: When To Delegate vs Do It Yourself

Claude Code can spawn isolated subagents for parts of a task. The trick is knowing when delegation actually helps — and when it just doubles your context bill.

10 min · Reviewed 2026

What subagents are

A subagent is a fresh Claude session spawned by the main agent for a scoped task. It gets its own context window, its own tool calls, and returns a summary back to the parent. The parent does not see the subagent's full transcript — it sees the result.

When subagents help

Searching a large codebase: subagent reads many files, returns a focused summary
Parallel exploration: spawn 3 subagents to investigate 3 hypotheses in parallel
Wide refactors where each module is independent and self-contained
Repeated, scoped work (apply the same change in 12 places, each in its own subagent)
When the parent's context is too valuable to spend on a sub-task

When subagents don't help

Tightly coupled work where the parent needs to see the actual code
Tasks that are short enough to do inline (under 5-10k tokens of effort)
Work where the subagent's context is the same as the parent's anyway
Anything the parent can do faster than spinning up a new agent
Quality-sensitive work where you want to read the full reasoning trace

The delegation prompt

Bad spawn prompt	Good spawn prompt
'Look at the auth code'	'Read every file under src/auth/. Identify any place we trust user-supplied input. Return a list with file:line and the exact line.'
'Refactor this'	'Apply the renamed-field migration in src/server/users.ts only. Update tests. Return the diff.'
'Investigate why tests fail'	'Run pnpm test. Read the failure output. Return the failing test names with one-line root-cause guesses.'

Apply: delegate one task today

Pick a wide read task in a codebase you're learning
Write a precise spawn prompt with a defined return shape
Run it as a subagent
Compare what came back to what you'd have done yourself
Refine the prompt for next time

The big idea: subagents are great when a task can be cleanly scoped and the return value can be summarized. Otherwise they're just expensive parallelism.

End-of-lesson check

15 questions · take it digitally for instant feedback at tendril.neural-forge.io/learn/quiz/end-claude-code-subagents-creators

What is the core idea behind "Subagents: When To Delegate vs Do It Yourself"?
1. Claude Code can spawn isolated subagents for parts of a task. The trick is knowing when delegation actually helps — and when it just doubles your context bill.
2. CLAUDE.md
3. review gate
4. custom command
Which term best describes a foundational idea in "Subagents: When To Delegate vs Do It Yourself"?
1. context isolation
2. subagent
3. delegation cost
4. spawn prompt
A learner studying Subagents: When To Delegate vs Do It Yourself would need to understand which concept?
1. subagent
2. delegation cost
3. context isolation
4. spawn prompt
Which of these is directly relevant to Subagents: When To Delegate vs Do It Yourself?
1. subagent
2. context isolation
3. spawn prompt
4. delegation cost
Which of the following is a key point about Subagents: When To Delegate vs Do It Yourself?
1. Searching a large codebase: subagent reads many files, returns a focused summary
2. Parallel exploration: spawn 3 subagents to investigate 3 hypotheses in parallel
3. Wide refactors where each module is independent and self-contained
4. Repeated, scoped work (apply the same change in 12 places, each in its own subagent)
Which of these does NOT belong in a discussion of Subagents: When To Delegate vs Do It Yourself?
1. CLAUDE.md
2. Parallel exploration: spawn 3 subagents to investigate 3 hypotheses in parallel
3. Searching a large codebase: subagent reads many files, returns a focused summary
4. Wide refactors where each module is independent and self-contained
Which statement is accurate regarding Subagents: When To Delegate vs Do It Yourself?
1. Tasks that are short enough to do inline (under 5-10k tokens of effort)
2. Work where the subagent's context is the same as the parent's anyway
3. Tightly coupled work where the parent needs to see the actual code
4. Anything the parent can do faster than spinning up a new agent
Which of these does NOT belong in a discussion of Subagents: When To Delegate vs Do It Yourself?
1. Work where the subagent's context is the same as the parent's anyway
2. CLAUDE.md
3. Tasks that are short enough to do inline (under 5-10k tokens of effort)
4. Tightly coupled work where the parent needs to see the actual code
What is the key insight about "The summary is the whole product" in the context of Subagents: When To Delegate vs Do It Yourself?
1. A subagent that produces a vague summary wastes everyone's time.
2. CLAUDE.md
3. review gate
4. custom command
What is the key insight about "Subagents double your tokens" in the context of Subagents: When To Delegate vs Do It Yourself?
1. CLAUDE.md
2. Each subagent is a separate run with its own token cost. Three parallel subagents are roughly 3x the spend of one.
3. review gate
4. custom command
What is the key insight about "From the community" in the context of Subagents: When To Delegate vs Do It Yourself?
1. CLAUDE.md
2. review gate
3. On r/ClaudeAI, the most-quoted token math is that multi-subagent workflows run roughly 4-7x the tokens of a single-agent…
4. custom command
Which statement accurately describes an aspect of Subagents: When To Delegate vs Do It Yourself?
1. CLAUDE.md
2. review gate
3. custom command
4. A subagent is a fresh Claude session spawned by the main agent for a scoped task.
What does working with Subagents: When To Delegate vs Do It Yourself typically involve?
1. The big idea: subagents are great when a task can be cleanly scoped and the return value can be summarized.
2. CLAUDE.md
3. review gate
4. custom command
Which best describes the scope of "Subagents: When To Delegate vs Do It Yourself"?
1. It is unrelated to tools workflows
2. It focuses on Claude Code can spawn isolated subagents for parts of a task. The trick is knowing when delegation a
3. It applies only to the opposite beginner tier
4. It was deprecated in 2024 and no longer relevant
Which section heading best belongs in a lesson about Subagents: When To Delegate vs Do It Yourself?
1. CLAUDE.md
2. review gate
3. When subagents help
4. custom command

← Back to interactive lesson

Tendril · Creators · Tools Literacy

Subagents: When To Delegate vs Do It Yourself

Claude Code can spawn isolated subagents for parts of a task. The trick is knowing when delegation actually helps — and when it just doubles your context bill.

10 min · Reviewed 2026

What subagents are

When subagents help

Searching a large codebase: subagent reads many files, returns a focused summary
Parallel exploration: spawn 3 subagents to investigate 3 hypotheses in parallel
Wide refactors where each module is independent and self-contained
Repeated, scoped work (apply the same change in 12 places, each in its own subagent)
When the parent's context is too valuable to spend on a sub-task

When subagents don't help

Tightly coupled work where the parent needs to see the actual code
Tasks that are short enough to do inline (under 5-10k tokens of effort)
Work where the subagent's context is the same as the parent's anyway
Anything the parent can do faster than spinning up a new agent
Quality-sensitive work where you want to read the full reasoning trace

The delegation prompt

Bad spawn prompt	Good spawn prompt
'Look at the auth code'	'Read every file under src/auth/. Identify any place we trust user-supplied input. Return a list with file:line and the exact line.'
'Refactor this'	'Apply the renamed-field migration in src/server/users.ts only. Update tests. Return the diff.'
'Investigate why tests fail'	'Run pnpm test. Read the failure output. Return the failing test names with one-line root-cause guesses.'

Apply: delegate one task today

Pick a wide read task in a codebase you're learning
Write a precise spawn prompt with a defined return shape
Run it as a subagent
Compare what came back to what you'd have done yourself
Refine the prompt for next time

The big idea: subagents are great when a task can be cleanly scoped and the return value can be summarized. Otherwise they're just expensive parallelism.

End-of-lesson check

15 questions · take it digitally for instant feedback at tendril.neural-forge.io/learn/quiz/end-claude-code-subagents-creators

What is the core idea behind "Subagents: When To Delegate vs Do It Yourself"?
1. Claude Code can spawn isolated subagents for parts of a task. The trick is knowing when delegation actually helps — and when it just doubles your context bill.
2. CLAUDE.md
3. review gate
4. custom command
Which term best describes a foundational idea in "Subagents: When To Delegate vs Do It Yourself"?
1. context isolation
2. subagent
3. delegation cost
4. spawn prompt
A learner studying Subagents: When To Delegate vs Do It Yourself would need to understand which concept?
1. subagent
2. delegation cost
3. context isolation
4. spawn prompt
Which of these is directly relevant to Subagents: When To Delegate vs Do It Yourself?
1. subagent
2. context isolation
3. spawn prompt
4. delegation cost
Which of the following is a key point about Subagents: When To Delegate vs Do It Yourself?
1. Searching a large codebase: subagent reads many files, returns a focused summary
2. Parallel exploration: spawn 3 subagents to investigate 3 hypotheses in parallel
3. Wide refactors where each module is independent and self-contained
4. Repeated, scoped work (apply the same change in 12 places, each in its own subagent)
Which of these does NOT belong in a discussion of Subagents: When To Delegate vs Do It Yourself?
1. CLAUDE.md
2. Parallel exploration: spawn 3 subagents to investigate 3 hypotheses in parallel
3. Searching a large codebase: subagent reads many files, returns a focused summary
4. Wide refactors where each module is independent and self-contained
Which statement is accurate regarding Subagents: When To Delegate vs Do It Yourself?
1. Tasks that are short enough to do inline (under 5-10k tokens of effort)
2. Work where the subagent's context is the same as the parent's anyway
3. Tightly coupled work where the parent needs to see the actual code
4. Anything the parent can do faster than spinning up a new agent
Which of these does NOT belong in a discussion of Subagents: When To Delegate vs Do It Yourself?
1. Work where the subagent's context is the same as the parent's anyway
2. CLAUDE.md
3. Tasks that are short enough to do inline (under 5-10k tokens of effort)
4. Tightly coupled work where the parent needs to see the actual code
What is the key insight about "The summary is the whole product" in the context of Subagents: When To Delegate vs Do It Yourself?
1. A subagent that produces a vague summary wastes everyone's time.
2. CLAUDE.md
3. review gate
4. custom command
What is the key insight about "Subagents double your tokens" in the context of Subagents: When To Delegate vs Do It Yourself?
1. CLAUDE.md
2. Each subagent is a separate run with its own token cost. Three parallel subagents are roughly 3x the spend of one.
3. review gate
4. custom command
What is the key insight about "From the community" in the context of Subagents: When To Delegate vs Do It Yourself?
1. CLAUDE.md
2. review gate
3. On r/ClaudeAI, the most-quoted token math is that multi-subagent workflows run roughly 4-7x the tokens of a single-agent…
4. custom command
Which statement accurately describes an aspect of Subagents: When To Delegate vs Do It Yourself?
1. CLAUDE.md
2. review gate
3. custom command
4. A subagent is a fresh Claude session spawned by the main agent for a scoped task.
What does working with Subagents: When To Delegate vs Do It Yourself typically involve?
1. The big idea: subagents are great when a task can be cleanly scoped and the return value can be summarized.
2. CLAUDE.md
3. review gate
4. custom command
Which best describes the scope of "Subagents: When To Delegate vs Do It Yourself"?
1. It is unrelated to tools workflows
2. It focuses on Claude Code can spawn isolated subagents for parts of a task. The trick is knowing when delegation a
3. It applies only to the opposite beginner tier
4. It was deprecated in 2024 and no longer relevant
Which section heading best belongs in a lesson about Subagents: When To Delegate vs Do It Yourself?
1. CLAUDE.md
2. review gate
3. When subagents help
4. custom command

← Back to interactive lesson