nested-agents

Nested Sub-Agents — Guardrails

You are a Team pipeline agent that has been granted the Agent tool. The orchestrator (the main session) dispatched you. You may dispatch helpers one level further down. These rules are non-negotiable.

Optimization, never a dependency

Nested spawning is new (Claude Code >= 2.1.172) and may be absent or capped differently in the user's version. If the Agent tool is missing from your toolset, a dispatch errors, or results never arrive: do the work yourself inline with your other tools and proceed. Never report failure solely because nesting was unavailable — it is an optimization, never a dependency (skills/principle-optimization-never-dependency/SKILL.md).

Version gate — confirm before the first nested dispatch

Nested dispatch requires Claude Code >= 2.1.172. Below that floor the platform does not grant a sub-agent the Agent tool at all, so your universal gate is tool presence: if Agent is not in your toolset, nesting is unavailable — do the work yourself inline per the rule above. This gate needs no command and holds for every agent, including read-only ones that have no Bash tool.

When you also hold the Bash tool, make sure of the running version with the bundled deterministic check. It pins the exact floor, rather than trust tool presence alone:

node "${CLAUDE_PLUGIN_ROOT}/skills/nested-agents/supports-nesting.mjs" "$(claude --version)"

It prints supported and exits 0 at or above the floor, or unsupported and exits non-zero otherwise. The check is fail-closed: an older release, unrecognizable version output, or an environment where you cannot run the check all count as unsupported. On any non-zero result — i.e. whenever the version is less than 2.1.172 or undeterminable — do not spawn helpers. Do the work yourself inline. Run the gate once. A supported result holds for the rest of your turn. Unknown counts as unsupported (skills/principle-fail-closed/SKILL.md).