| name | generic-subagent |
| description | Context-efficient delegation to subagents (read-only default, READ-WRITE opt-in) |
Subagents offload context-expensive work. The caller receives a digest, not the full trace.
Default subagents are read-only (research, analyze, summarize). READ-WRITE subagents may modify state within declared scope.
When to Delegate
See the contract's Subagent Delegation Protocol for authoritative triggers.
Summary:
| Trigger | Threshold |
|---|
| Uncertain scope | Assess with cheap ops first → convert to defined |
| Content to read | >250KB of files to READ (not search scope) |
| Processing depth | >2 intermediate tool calls whose outputs aren't needed in final delivery |
Clarification on 250KB:
- Applies to
Read operations (full content enters context)
- Does NOT apply to
Grep (only matches enter context)
- Typical sequence: search (cheap) → identify matches → measure size of files to read → apply threshold
Keep Inline When
- Task requires user interaction mid-execution
- Result interpretation needs full conversation history
- Content to read ≤250KB and processing depth ≤2 steps
Delegation Protocol
1. Assess Scope (if uncertain)
stat --printf="%s\n" src/api/*.py | awk '{sum+=$1} END {print sum}'
2. Generate Brief
MODE: SUBAGENT
MODE: SUBAGENT READ-WRITE ← only when objective requires state changes
GOAL: {{objective}}
CONTEXT: {{what caller already knows — no pre-analysis required}}
SCOPE: {{files, directories, or boundaries}}
Brief principles:
- Write from existing knowledge only — if investigation is needed to specify the goal, that IS the delegated work
- Vague goals are valid when they reflect genuine uncertainty
- Subagent has the contract — don't repeat rules in the brief
3. Dispatch
Use Task tool. Subagent inherits contract but operates in Subagent Mode (no external gates, compressed output). Default is read-only; READ-WRITE permits state modification with mandatory Intent Gate per action.
3b. Model Selection
The CLAUDE_CODE_SUBAGENT_MODEL env var sets the default model.
Override it per-agent when the task doesn't need the default's reasoning:
| Task type | Model | Examples |
|---|
| Mechanical | haiku | grep, glob, file reads, size checks, find-and-list |
| Analytical | default | code review, architecture survey, dependency analysis |
| Judgment-heavy | opus | cross-module impact, ambiguous specs, security review |
Rule of thumb: if the brief could be expressed as a shell pipeline
but delegation is used for context isolation, use haiku.
For the Subagent
When receiving a MODE: SUBAGENT brief:
- Review ~/§BRAND_GLOBAL_DIRNAME§/AGENT_TOOLS.md — MCP servers often provide efficient alternatives to manual tool chains
- Work within scope, abort if insufficient
- Return structured output (see below)
4. Review Output
RESULT: [success | partial | blocked | failed]
SUMMARY: [what was found/analyzed]
CONCERNS: [issues for caller review]
BLOCKERS: [if not success — what prevented completion]
DETAILED RESPONSE: [findings]
Review: Verify result addresses goal intent. Address concerns before proceeding.
5. Integrate
- Success: Use digest, continue main task
- Partial: Complete inline or re-delegate with narrower scope
- Blocked/Failed: Surface to user or try alternative approach
Common Delegation Patterns
| Pattern | Goal Template |
|---|
| Find definition | "Find where {{symbol}} is defined and its signature" |
| Analyze dependencies | "List what {{module}} imports and what imports it" |
| Explore area | "Understand how {{area}} works" (vague is OK) |
| Search and summarize | "Find all {{pattern}} and summarize their purposes" |
| Architecture survey | "Identify the main components and their relationships in {{area}}" |
Anti-Patterns
Don't delegate:
- State-modifying operations without
READ-WRITE marker — default subagents are read-only
- Decisions requiring user input
- The debugging hypothesis loop (requires iterative testing with full context)
Exception — debugging research IS delegatable:
- "Find all call sites of function X"
- "Find working analogues for this pattern"
- "Check if error handling exists for case Y"
These support Bug Qualification / Pattern Analysis phases without owning the hypothesis loop.
Parallel Delegation
Independent research tasks can run simultaneously:
- Identify independent subtasks
- Generate briefs for each
- Dispatch in parallel (multiple Task tool calls)
- Await all results
- Integrate digests
Dependency awareness: If task B depends on task A's output, dispatch sequentially.