| name | token-budget |
| description | Context/token discipline: subagent isolation, output = summary, move-to-file, delegation threshold, lean skills.
Trigger phrases: "token", "context", "context management", "context is full", "clear context"
|
Token & Context Discipline
A subagent exists for context management: it runs in its own window and returns only its summary
to the main thread — intermediate noise (file reads, searches, logs) never enters the main context.
Warning — measured, not guessed. Each subagent re-pays its full context from scratch: in a real
transcript the first turn was cache_read=0, every token cache_creation — nothing is shared with the main
thread's cache. A no-op subagent (task = "reply DONE") already cost ~10k tokens with restricted tools and
~16k with full tool access; that floor is base system prompt + tool schemas, paid fresh every time. Of the
always-on material only the skill listing (~2.5–3k tokens) is inherited by a subagent — the discipline
(DISCIPLINE.md/CLAUDE.md) and the agent descriptions are not injected into it. So a delegation is worth it
for isolation / parallelism / a clean window, or when the isolated work would otherwise cost the main thread
more than that ~10–16k floor — never by default.
Rules
- Output = summary. The agent returns a short, structured summary to the main thread; it does not return raw logs / file dumps / long code.
- Move to a file. Heavy output (a plan, scan report, inventory) is written to
docs/*.md; a summary + pointer comes back. (local, in gitignore)
- Delegation threshold. Noisy/heavy work (reading many files, scanning, research) → subagent. A single tool-call / small work → main thread. Concretely: if the isolated work won't save the main thread more than the ~10–16k fresh-context floor a subagent costs, keep it on the main thread — delegate for isolation, not to shave a few reads.
- Least tooling. An agent holds only the tools it needs; extras accidentally pollute the context + burn the limit.
- Lean SKILL.md. Skills load into the main context; heavy reference goes to a separate file, only when needed.
- Targeted reading. Instead of reading a whole file, pinpoint with Grep/Glob.
- Manage with /context. session-manager-csk recommends continue/handoff+clear based on the real percentage; at a phase boundary,
/clear.
