subagent-isolation

When to Use

Maintain clean context boundaries between delegated agents —

Isolation Rules

Fresh context per delegation

Each delegate starts CLEAN. Include ALL context needed. Reference Engram IDs. File context -> paths + what to look for.

No cross-contamination

Rule	Why
Never share state between subagents	Prevents hallucination cascades
Independent tool access per subagent	Error isolation
Serialize if B depends on A	Don't parallelize dependent work

Dependency declaration

Declare what subagent needs (file paths, Engram IDs). NOT: full history, system prompt.

Result isolation

Each delegate returns OWN output. Conflicts -> raise to orchestrator. Subagents NEVER modify global state without explicit instructions.

Preservation contract

Every delegation output MUST include this 4-field block AS-IS (never summarized):

## Decision Taken    ## Files Changed
## Key Findings      ## Nuance (what detail would be lost if summarized)

Error boundaries

Error	Action
Timeout	Retry once with cleaner prompt, then escalate
Wrong output	Log to Engram, re-delegate with corrected context
Hallucinates	Flag as contamination -> check isolation rules

Anti-Rationalization

Rationalization	Red Flag	Verification
"compartir contexto entre subagentes ahorra tokens"	Reutilizar historial completo entre delegations	Cada delegate arranca CLEAN: solo paths + Engram IDs necesarios, nunca historial completo
"hallucination cascade se detecta sola"	No aislar, asumir errores no se propagan	Aplicar isolation rules: no shared state, error boundaries (timeout→retry once, hallucinate→flag contamination)
"un subagente puede editar archivos de otro sin coordinar"	Overlap de escritura sin dependency graph	Verificar no file overlap antes de paralelizar; si B depende de A → serial, conflictos → escalar a orchestrator

Red Flags

• Doing work without checking output format → STOP, re-read skill
• Second occurrence of same rationalization → force RED zone

Verification

• Output matches skill ## Output contract + file:line citaton
• cross-ref-check.ps1 → SKILL.md OK

Refs

delivery-harness · command-wrapper · lean-context · context-watchdog · execution-mode

Anti-Patterns

Share state between subagents · Parallelize dependent tasks · Skip 4-field contract · Keep full subagent output in context · No error isolation

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See reference.md for extended details, examples, and detailed patterns.