subagent-broker — Task-tool delegation patterns that actually work

Fixes: #4182, #5528, #19077

What this prevents

"Sub-agents claim no Task tool access despite configuration stating tools: Read, Write, Edit, Task. CRITICAL rules are completely disregarded. No actual delegation occurs." — issue #5528

"Sub-Agent Task tool not exposed when launching nested agents." — issue #4182

The Task tool is the official delegation mechanism, but it fails silently when the delegation prompt isn't structured right:

• Open-ended prompts return shallow output
• "CRITICAL" / "ALWAYS" directives are ignored
• Briefed-with-conclusion prompts produce sycophantic "yes" answers
• Subagent results aren't shared between subagents (people assume they are)

subagent-broker ships the prompt skeletons that survive these pitfalls — distilled from the issue threads themselves.

The templates

How to invoke (the actual procedure)

1. Run the templates script to see what's available:

   ${CLAUDE_PLUGIN_ROOT}/skills/subagent-broker/templates.py

1. Ask the user which delegation flavor matches their task:

• Parallel search across the codebase → parallel-search
• One deep research question → single-research
• Cross-file consistency check → cross-file-audit
• "I know exactly which file I need" → known-target (don't delegate)
• Second opinion / independent review → independent-verification

1. Print the chosen template:

   ${CLAUDE_PLUGIN_ROOT}/skills/subagent-broker/templates.py <name>

1. Adapt the placeholders (<files>, <specific concern>, etc.) to

the user's actual task. Then make the Task call yourself.

1. Never invoke Task blindly. The user should see the proposed

delegation prompt and approve it before you fire.

The non-obvious rules (from the issues)

• State the most-important constraint twice. Once near the top of

the prompt, once in the response-format section. CRITICAL / ALWAYS keywords don't help; placement does. (issue #5528)

• Cap the response length explicitly. Subagents will read every

file they find if you don't tell them not to.

• Parallelize in a single message. Two Task calls in two

consecutive messages run sequentially. Two Task calls in the same message run in parallel.

• Don't tell the subagent your conclusion. They'll anchor on it.

For verification, withhold your analysis.

• Subagents are 5-10× more expensive than a direct tool call.

Delegate only when the subagent will make 3+ tool calls.

When to auto-invoke

• User runs /claude-papercuts:subagent-broker
• User asks how to use Task / subagents / delegation
• User says subagents ignore their config / CRITICAL rules
• User wants a template for parallel work / cross-file review

What this skill does NOT do

• It does not fire the Task tool for you. You (Claude) call Task

yourself with the adapted template — the user reviews the prompt first.

• It does not validate that your delegation succeeded. The

subagent's own output is the verdict.

• It is not a queue / dispatcher. Earlier drafts of this skill

shipped a queue + spawn system; we cut it because it duplicates what Anthropic's Task tool already does.

Configuration

# List every template
${CLAUDE_PLUGIN_ROOT}/skills/subagent-broker/templates.py

# Print one ready to paste
${CLAUDE_PLUGIN_ROOT}/skills/subagent-broker/templates.py parallel-search

# Filter by keyword
${CLAUDE_PLUGIN_ROOT}/skills/subagent-broker/templates.py --search research

# Machine-readable
${CLAUDE_PLUGIN_ROOT}/skills/subagent-broker/templates.py --json

Deprecation plan

If Anthropic ships first-class delegation reliability (per issues #4182, #5528, #19077), the templates become less load-bearing and this skill can simplify or deprecate.