diff --git a/packages/coding-agent/CHANGELOG.md b/packages/coding-agent/CHANGELOG.md
index ce8a4f32d..c4935ec9d 100644
--- a/packages/coding-agent/CHANGELOG.md
+++ b/packages/coding-agent/CHANGELOG.md
@@ -5,6 +5,7 @@
 ### Changed
 
 - Made the task tool's per-spawn `effort` parameter opt-in through `task.enableEffort`, which defaults to false and omits the field from flat and batch schemas and tool guidance until enabled.
+- Added `task.maxEffort` to cap the task tool's optional per-spawn effort hint after model-specific resolution, so operators can enable effort hints without allowing them to exceed a configured ceiling ([#6580](https://github.com/can1357/oh-my-pi/issues/6580)).
 
 ### Fixed
 
diff --git a/packages/coding-agent/src/config/settings-schema.ts b/packages/coding-agent/src/config/settings-schema.ts
index 9971ba8ab..afa0ee8ab 100644
--- a/packages/coding-agent/src/config/settings-schema.ts
+++ b/packages/coding-agent/src/config/settings-schema.ts
@@ -4600,6 +4600,20 @@ export const SETTINGS_SCHEMA = {
 		},
 	},
 
+	"task.maxEffort": {
+		type: "enum",
+		values: THINKING_EFFORTS,
+		default: "max",
+		ui: {
+			tab: "tasks",
+			group: "Subagents",
+			label: "Maximum Per-Spawn Effort",
+			description:
+				"Maximum reasoning effort allowed for the task tool's per-spawn effort hint. Lower values prevent callers from escalating subagents above this ceiling; the default preserves the model's full range.",
+			options: THINKING_EFFORTS.map(getThinkingLevelMetadata),
+		},
+	},
+
 	"task.disabledAgents": {
 		type: "array",
 		default: [] as string[],
diff --git a/packages/coding-agent/src/task/executor.ts b/packages/coding-agent/src/task/executor.ts
index 97c1d83d2..6fa4c0dd4 100644
--- a/packages/coding-agent/src/task/executor.ts
+++ b/packages/coding-agent/src/task/executor.ts
@@ -2647,9 +2647,13 @@ export async function runSubprocess(options: ExecutorOptions): Promise<SingleRes
 				progress.contextWindow = model.contextWindow;
 			}
 			// Caller-requested coarse effort maps onto the resolved model's
-			// supported range; undefined (no effort, or no controllable effort
-			// surface) falls through to the normal selectors below.
-			const effortLevel = options.effort !== undefined ? resolveTaskEffortLevel(model, options.effort) : undefined;
+			// supported range, then respects the operator-configured ceiling.
+			// Undefined (no effort, or no controllable effort surface) falls
+			// through to the normal selectors below.
+			const effortLevel =
+				options.effort !== undefined
+					? resolveTaskEffortLevel(model, options.effort, settings.get("task.maxEffort"))
+					: undefined;
 			if (model) {
 				const displayLevel = effortLevel ?? (explicitThinkingLevel ? resolvedThinkingLevel : undefined);
 				progress.resolvedModel =
diff --git a/packages/coding-agent/src/thinking.ts b/packages/coding-agent/src/thinking.ts
index 15e5d1869..a59d65d25 100644
--- a/packages/coding-agent/src/thinking.ts
+++ b/packages/coding-agent/src/thinking.ts
@@ -273,17 +273,29 @@ export type TaskEffort = (typeof TASK_EFFORTS)[number];
  * Returns `undefined` when the model has no controllable effort surface, so
  * callers fall back to their default selector (e.g. `auto`).
  */
-export function resolveTaskEffortLevel(model: Model | undefined, effort: TaskEffort): Effort | undefined {
+export function resolveTaskEffortLevel(
+	model: Model | undefined,
+	effort: TaskEffort,
+	maxEffort?: Effort,
+): Effort | undefined {
 	const supported = model ? getSupportedEfforts(model) : THINKING_EFFORTS;
 	if (supported.length === 0) return undefined;
+	let resolved: Effort;
 	switch (effort) {
 		case "lo":
-			return supported[0];
+			resolved = supported[0];
+			break;
 		case "med":
-			return supported[(supported.length - 1) >> 1];
+			resolved = supported[(supported.length - 1) >> 1];
+			break;
 		case "hi":
-			return supported[supported.length - 1];
+			resolved = supported[supported.length - 1];
+			break;
 	}
+	if (maxEffort === undefined) return resolved;
+	const ceiling = clampThinkingLevelForModel(model, maxEffort);
+	if (ceiling === undefined) return resolved;
+	return THINKING_EFFORTS.indexOf(resolved) > THINKING_EFFORTS.indexOf(ceiling) ? ceiling : resolved;
 }
 
 /**
diff --git a/packages/coding-agent/test/task/executor-pass-through.test.ts b/packages/coding-agent/test/task/executor-pass-through.test.ts
index c18c93231..339568181 100644
--- a/packages/coding-agent/test/task/executor-pass-through.test.ts
+++ b/packages/coding-agent/test/task/executor-pass-through.test.ts
@@ -233,6 +233,48 @@ describe("runSubprocess parent-discovery pass-through (issue #2190)", () => {
 		expect(Object.hasOwn(result, "structuredOutput")).toBe(false);
 	});
 
+	it("caps caller-requested effort at task.maxEffort", async () => {
+		const model = getBundledModel("openai-codex", "gpt-5.6-sol");
+		if (!model) throw new Error("Expected gpt-5.6-sol model to exist");
+		const settings = Settings.isolated({ "task.maxEffort": "low" });
+		settings.setModelRole("task", `${model.provider}/${model.id}`);
+		const session = yieldEmittingSession();
+		const spy = vi.spyOn(sdkModule, "createAgentSession").mockResolvedValue(createSessionResult(session));
+
+		const result = await runSubprocess({
+			...baseOptions,
+			agent: { ...baseAgent, model: ["@task"] },
+			id: "subagent-effort-ceiling",
+			effort: "hi",
+			settings,
+			modelRegistry: createModelRegistry(model),
+		});
+
+		expect(result.exitCode).toBe(0);
+		expect(spy.mock.calls[0]?.[0]?.thinkingLevel).toBe(ThinkingLevel.Low);
+	});
+
+	it("preserves the model's full effort range by default", async () => {
+		const model = getBundledModel("openai-codex", "gpt-5.6-sol");
+		if (!model) throw new Error("Expected gpt-5.6-sol model to exist");
+		const settings = Settings.isolated();
+		settings.setModelRole("task", `${model.provider}/${model.id}`);
+		const session = yieldEmittingSession();
+		const spy = vi.spyOn(sdkModule, "createAgentSession").mockResolvedValue(createSessionResult(session));
+
+		const result = await runSubprocess({
+			...baseOptions,
+			agent: { ...baseAgent, model: ["@task"] },
+			id: "subagent-default-effort-ceiling",
+			effort: "hi",
+			settings,
+			modelRegistry: createModelRegistry(model),
+		});
+
+		expect(result.exitCode).toBe(0);
+		expect(spy.mock.calls[0]?.[0]?.thinkingLevel).toBe(ThinkingLevel.Max);
+	});
+
 	it("resolves an explicit task-role effort suffix over the agent-definition default", async () => {
 		const model = getBundledModel("anthropic", "claude-sonnet-4-5");
 		if (!model) throw new Error("Expected claude-sonnet-4-5 model to exist");