How to Give AI Subagents the Right Project Context
A practical way to brief AI subagents with the files, constraints, decisions, and success checks they need without sending the full prompt.
Large repeated prompt
Unrelated decisions and files
Worker must rediscover the real assignment
Small token budget
Task-relevant context with provenance
Explicit deliverable, success checks, and return format
A useful AI subagent brief is not a compressed transcript. It is a task contract. The worker needs enough project context to act correctly, but every unrelated detail makes the assignment harder to parse and more expensive to run.
What an AI subagent needs
Start with the role and concrete deliverable. Then define success, name the likely files or folders, include only decisions and constraints that change the implementation, state known landmines, and give the worker a verification command or check. Finish with exactly what the worker should return to the orchestrator.
What to leave out
Do not forward the entire chat, every historic decision, the complete repository map, or broad product background that does not affect the assignment. The orchestrator should retain that global context and package only the relevant slice for each worker.
Why retrieval matters
Handwritten worker prompts often miss the one constraint that matters. A project context system can rank known paths, current decisions, recurring rules, blockers, debugging findings, and commands against the task. Provenance makes the package inspectable, while a fixed token budget forces relevance.
A reliable subagent brief format
Use consistent sections: role, deliverable, success criteria, project facts to know, files to work in, landmines, verification, and return format. Consistency helps the worker find instructions quickly and helps the orchestrator compare results across parallel tasks.
How DeerDawn automates it
DeerDawn’s build_subagent_brief MCP tool takes a task and optional role, deliverable, acceptance criteria, focus paths, verification steps, and token limit. It selects project-scoped context, sanitizes it, deduplicates paths, and returns a compact brief ready for an isolated worker.
The orchestration pattern
Keep one rich project brief at the orchestrator level. Generate a separate small brief for every concrete subtask. Launch each worker with no conversation history beyond its brief, then merge the worker’s findings or changes back at the orchestrator.
Never start cold
Set up DeerDawn once and it briefs every new session with your project's current state, so Claude Code, Cursor, Codex, Claude.ai, and ChatGPT all start caught up instead of cold.