Remove unreachable AgentProfile.fleetTier

No loader ever populated it from any config format, so profile-sourced
orchestrators always resolved to leaf. Fail-closed denial of fleet verbs
is unchanged; CL-6942/CL-6944 can add a real opt-in when a caller needs one.

Author: TheGreatAxios

CHANGELOG.md

@@ -11,6 +11,15 @@ matching `## [X.Y.Z]` section (plus install instructions). Do not maintain
 parallel copies under `docs/` or `scripts/notes/`. At cut time: rename
 `## [Unreleased]` to `## [X.Y.Z] - YYYY-MM-DD`, then run the release script.
 
+## [Unreleased]
+
+### Agent
+
+- Removed `AgentProfile.fleetTier`: no loader ever populated it from any config
+  format, so it was declared but unreachable. Fail-closed behavior is
+  unchanged — a profile-sourced orchestrator is still denied `task`/
+  `search_agents` with no supported opt-in.
+
 ## [0.2.108] - 2026-08-24
 
 ### Agent

docs/ARCHITECTURE.md

@@ -239,7 +239,7 @@ Every director package carries a required `tier: SubagentTier` field (`src/agent
 
 Enforcement is runtime code at the existing tool-mount point, not prompt wording — this is the fix for four prior mechanisms (`writePaths`, `report.requiredSections`, a `--config` comment, the thrash matcher) that were documented-as-enforced while enforcing nothing:
 
-- **Mount-time gate — live today, and fails closed.** `task-tool.ts` resolves the caller's tier at dispatch time — a closed director's `DirectorPackage.tier`, or an explicit non-leaf `AgentProfile.fleetTier` opt-in for a profile-sourced orchestrator — and forwards it as `RunSubAgentParams.orchestratorTier`. `runSubAgent` (`src/subagent/run.ts`) then calls `assertTierMayMountFleetVerb(tier, toolName)` (`src/subagent/authority.ts`) before installing `task` / `search_agents`, treating a **missing** `orchestratorTier` as `"leaf"` — deny, not skip. This is the case that matters most: a project-local or plugin `AgentProfile` with `orchestrator: true` is outside the closed director set and is **not** trusted with fleet verbs just because `orchestrator: true` is set — it must also declare `fleetTier: "nested-orchestrator"`, or the mount throws `FleetAuthorityError`. (`AgentProfile.fleetTier` is deliberately not named `tier` — that name is already used, ad hoc, by some profiles for an unrelated model-speed selector; reusing it would have silently broken schema validation for those profiles, which is exactly what happened during review and was caught by the full test suite, not by inspection.) `FLEET_VERBS` in `authority.ts` also names the not-yet-implemented verbs (`spawn_agent`, `wait_agents`, `list_agents`, `send_input`, `interrupt_agent`, `close_agent`, `resume_agent`, `read_agent_trace`, `followup_task`) so their future mount sites inherit the same gate.
+- **Mount-time gate — live today, and fails closed.** `task-tool.ts` resolves the caller's tier at dispatch time — a closed director's `DirectorPackage.tier` — and forwards it as `RunSubAgentParams.orchestratorTier`. `runSubAgent` (`src/subagent/run.ts`) then calls `assertTierMayMountFleetVerb(tier, toolName)` (`src/subagent/authority.ts`) before installing `task` / `search_agents`, treating a **missing** `orchestratorTier` as `"leaf"` — deny, not skip. This is the case that matters most: a project-local or plugin `AgentProfile` with `orchestrator: true` is outside the closed director set and is **not** trusted with fleet verbs just because `orchestrator: true` is set — there is no profile-level opt-in today, so the mount always throws `FleetAuthorityError` for a profile-sourced orchestrator (CL-6942/CL-6944 can add one when a real caller needs it). `FLEET_VERBS` in `authority.ts` also names the not-yet-implemented verbs (`spawn_agent`, `wait_agents`, `list_agents`, `send_input`, `interrupt_agent`, `close_agent`, `resume_agent`, `read_agent_trace`, `followup_task`) so their future mount sites inherit the same gate.
 - **Subtree authority — a seam, not yet wired.** `assertCanTargetAgent(actor, targetId, nodes)` (`src/subagent/authority.ts`) implements the "root owns its tree; a child manages only its own descendants" rule (Tier 1 may target anyone, Tier 2 may target only its own descendants over the same `{id, parentSessionId}` shape `SubAgentSessionStore` already tracks, Tier 3 always fails closed) — but **it has no production call site yet**. No verb today lets one live agent address another (`task` only spawns), so this rule is exercised only by `authority.test.ts` and is not enforced at runtime in this PR. It exists so CL-6942 (split spawn from wait) and CL-6944 (`send_input` steering) — the first verbs that make an agent addressable by another — can call it from day one instead of each inventing its own check. Treat it as unenforced until one of those wires a call site.
 - `task()` is unaffected and remains the only spawn verb until the new verbs land beside it (deprecated-not-deleted per the CL-6940 epic). Its argument schema and wire contract are unchanged; the tier check only gates which packages may have it mounted at all.
 

src/agent/profile-types.ts

@@ -68,18 +68,6 @@ export interface AgentProfile {
   // coordinators (e.g. a planning agent that fans work out to specialists);
   // leaf-task agents should leave this unset.
   orchestrator?: boolean;
-  // Fleet authority tier (CL-6941) for a profile-sourced orchestrator. Only
-  // meaningful alongside orchestrator: true. Named `fleetTier`, not `tier` —
-  // `tier` is already an established profile field for model speed selection
-  // ("fast" | "standard" | "clever", resolved via task(tier=...)); reusing
-  // the name silently broke schema validation for profiles that set it. A
-  // profile is outside the closed director set, so it is NOT trusted with
-  // fleet verbs by default even when orchestrator: true is set — this must
-  // be declared explicitly as "nested-orchestrator" to opt in.
-  // Runtime-enforced at the tool-mount point (src/subagent/run.ts /
-  // src/subagent/authority.ts): an orchestrator=true profile with no
-  // fleetTier (or fleetTier: "leaf") is denied task/search_agents, fail-closed.
-  fleetTier?: "orchestrator" | "nested-orchestrator" | "leaf";
   // Optional inference-turn budget when this profile is dispatched via task(agent=...).
   // Floor-sanitized (≥1) at dispatch time; task(maxTurns) overrides when set.
   maxTurns?: number;

src/agent/profiles.ts

@@ -51,7 +51,6 @@ const AgentProfileSchema = type({
   "systemPromptRole?": "string",
   "systemPromptPath?": "string",
   "orchestrator?": "boolean",
-  "fleetTier?": "'orchestrator' | 'nested-orchestrator' | 'leaf'",
   "maxTurns?": "number",
 });
 

src/subagent/task-tool.ts

@@ -486,14 +486,9 @@ export function createTaskTool(deps: TaskToolDeps): AgentTool {
           if (profile.orchestrator === true && deps.allowOrchestrator !== false) {
             orchestrator = true;
             // Fail closed (CL-6941): a profile is outside the closed director
-            // set, so orchestrator: true alone does not grant a tier. Only an
-            // explicit non-leaf profile.fleetTier opts in; anything else
-            // (absent, or "leaf") leaves orchestratorTier undefined, which
+            // set, so orchestrator: true alone does not grant a tier. No
+            // profile field opts in; orchestratorTier stays undefined, which
             // runSubAgent treats as "leaf" and denies task/search_agents.
-            orchestratorTier =
-              profile.fleetTier !== undefined && profile.fleetTier !== "leaf"
-                ? profile.fleetTier
-                : undefined;
           }
           // Per-agent pinned inference (provider/model/effort), if declared.
           // Resolution uses policy (mode: pin / agentModelFallback: none) so a

tests/unit/subagent.test.ts

@@ -972,5 +972,9 @@ describe("createTaskTool profile resolution", () => {
     await callHandler(tool, { description: "task", prompt: "do it", agent: "karen" });
 
     expect(received?.orchestrator).toBe(true);
+    // Fail-closed (CL-6941): no profile field opts a profile-sourced
+    // orchestrator into fleet verbs, so the tier stays unresolved and
+    // runSubAgent treats it as "leaf" — denied task/search_agents.
+    expect(received?.orchestratorTier).toBeUndefined();
   });
 });