diff --git a/src/artifacts.test.ts b/src/artifacts.test.ts
index 7d444c4..e2143fe 100644
--- a/src/artifacts.test.ts
+++ b/src/artifacts.test.ts
@@ -11,11 +11,12 @@ test("createRunArtifacts writes metadata and reserves stable artifact paths", as
   const artifacts = await createRunArtifacts(cwd, {
     runId: "run-1",
     task: "inspect auth",
-    systemPrompt: "You are scout",
   });
 
   assert.equal(artifacts.runId, "run-1");
   assert.match(artifacts.dir, /\.pi\/subagents\/runs\/run-1$/);
-  assert.equal(JSON.parse(await readFile(artifacts.metaPath, "utf8")).task, "inspect auth");
-  assert.equal(await readFile(artifacts.systemPromptPath, "utf8"), "You are scout");
+  const meta = JSON.parse(await readFile(artifacts.metaPath, "utf8"));
+  assert.equal(meta.task, "inspect auth");
+  assert.equal("systemPromptPath" in meta, false);
+  await assert.rejects(readFile(join(artifacts.dir, "system-prompt.md"), "utf8"));
 });
diff --git a/src/artifacts.ts b/src/artifacts.ts
index b4ffd73..0dbe3ce 100644
--- a/src/artifacts.ts
+++ b/src/artifacts.ts
@@ -12,12 +12,11 @@ export interface RunArtifacts {
   stderrPath: string;
   transcriptPath: string;
   sessionPath: string;
-  systemPromptPath: string;
 }
 
 export async function createRunArtifacts(
   cwd: string,
-  meta: Record<string, unknown> & { runId?: string; systemPrompt?: string },
+  meta: Record<string, unknown> & { runId?: string },
 ): Promise<RunArtifacts> {
   const runId = meta.runId ?? randomUUID();
   const dir = resolve(cwd, ".pi", "subagents", "runs", runId);
@@ -33,7 +32,6 @@ export async function createRunArtifacts(
     stderrPath: join(dir, "stderr.log"),
     transcriptPath: join(dir, "transcript.log"),
     sessionPath: join(dir, "child-session.jsonl"),
-    systemPromptPath: join(dir, "system-prompt.md"),
   };
 
   await writeFile(
@@ -48,7 +46,6 @@ export async function createRunArtifacts(
         stdoutPath: artifacts.stdoutPath,
         stderrPath: artifacts.stderrPath,
         transcriptPath: artifacts.transcriptPath,
-        systemPromptPath: artifacts.systemPromptPath,
       },
       null,
       2,
@@ -56,7 +53,6 @@ export async function createRunArtifacts(
     "utf8",
   );
 
-  await writeFile(artifacts.systemPromptPath, typeof meta.systemPrompt === "string" ? meta.systemPrompt : "", "utf8");
   await writeFile(artifacts.eventsPath, "", "utf8");
   await writeFile(artifacts.stdoutPath, "", "utf8");
   await writeFile(artifacts.stderrPath, "", "utf8");
diff --git a/src/process-runner.test.ts b/src/process-runner.test.ts
index 19486dc..a65f993 100644
--- a/src/process-runner.test.ts
+++ b/src/process-runner.test.ts
@@ -30,8 +30,6 @@ test("createProcessSingleRunner launches wrapper without tmux and returns monito
             {
               runId: meta.runId,
               mode: meta.mode,
-              agent: meta.agent,
-              agentSource: meta.agentSource,
               task: meta.task,
               requestedModel: meta.requestedModel,
               resolvedModel: meta.resolvedModel,
@@ -60,8 +58,6 @@ test("createProcessSingleRunner launches wrapper without tmux and returns monito
     cwd,
     meta: {
       mode: "single",
-      agent: "scout",
-      agentSource: "builtin",
       task: "inspect auth",
       requestedModel: "openai/gpt-5",
       resolvedModel: "openai/gpt-5",
@@ -95,8 +91,6 @@ test("createProcessSingleRunner writes error result.json when wrapper launch fai
     cwd,
     meta: {
       mode: "single",
-      agent: "scout",
-      agentSource: "builtin",
       task: "inspect auth",
       requestedModel: "openai/gpt-5",
       resolvedModel: "openai/gpt-5",
@@ -109,5 +103,6 @@ test("createProcessSingleRunner writes error result.json when wrapper launch fai
 
   const saved = JSON.parse(await readFile(result.resultPath!, "utf8"));
   assert.equal(saved.exitCode, 1);
+  assert.equal("agent" in saved, false);
   assert.match(saved.errorMessage ?? "", /spawn boom/);
 });
diff --git a/src/process-runner.ts b/src/process-runner.ts
index f612ca3..1f4cbf8 100644
--- a/src/process-runner.ts
+++ b/src/process-runner.ts
@@ -11,8 +11,6 @@ function makeLaunchFailureResult(artifacts: any, meta: Record<string, unknown>,
     mode: meta.mode,
     taskIndex: meta.taskIndex,
     step: meta.step,
-    agent: meta.agent,
-    agentSource: meta.agentSource,
     task: meta.task,
     cwd,
     requestedModel: meta.requestedModel,
diff --git a/src/wrapper/cli.mjs b/src/wrapper/cli.mjs
index 47c5ff6..ada1d90 100644
--- a/src/wrapper/cli.mjs
+++ b/src/wrapper/cli.mjs
@@ -34,8 +34,6 @@ function makeResult(meta, startedAt, input = {}) {
     mode: meta.mode,
     taskIndex: meta.taskIndex,
     step: meta.step,
-    agent: meta.agent,
-    agentSource: meta.agentSource,
     task: meta.task,
     cwd: meta.cwd,
     requestedModel: meta.requestedModel,
@@ -69,8 +67,6 @@ async function runWrapper(meta, startedAt) {
 
   const args = ["--mode", "json", "--session", meta.sessionPath];
   if (effectiveModel) args.push("--model", effectiveModel);
-  if (Array.isArray(meta.tools) && meta.tools.length > 0) args.push("--tools", meta.tools.join(","));
-  if (meta.systemPromptPath) args.push("--append-system-prompt", meta.systemPromptPath);
   args.push(meta.task);
 
   let finalText = "";
diff --git a/src/wrapper/cli.test.ts b/src/wrapper/cli.test.ts
index 30a4954..37a6361 100644
--- a/src/wrapper/cli.test.ts
+++ b/src/wrapper/cli.test.ts
@@ -32,8 +32,6 @@ async function runWrapperWithFakePi(requestedModel: string, resolvedModel?: stri
   const capturePath = join(dir, "capture.json");
   const piPath = join(dir, "pi");
 
-  // The fake `pi` is a small Node script that writes a JSON capture file
-  // including relevant PI_* environment variables and the argv it received.
   const resolved = typeof resolvedModel === "string" ? resolvedModel : requestedModel;
   await writeFile(
     piPath,
@@ -59,8 +57,6 @@ async function runWrapperWithFakePi(requestedModel: string, resolvedModel?: stri
       {
         runId: "run-1",
         mode: "single",
-        agent: "scout",
-        agentSource: "builtin",
         task: "inspect auth",
         cwd: dir,
         requestedModel,
@@ -72,6 +68,7 @@ async function runWrapperWithFakePi(requestedModel: string, resolvedModel?: stri
         stdoutPath: join(dir, "stdout.log"),
         stderrPath: join(dir, "stderr.log"),
         transcriptPath: join(dir, "transcript.log"),
+        tools: ["read", "grep"],
         systemPromptPath: join(dir, "system-prompt.md"),
       },
       null,
@@ -96,7 +93,6 @@ async function runWrapperWithFakePi(requestedModel: string, resolvedModel?: stri
   return { flags: captureJson };
 }
 
-// Dedicated tests: every child run must have PI_SUBAGENTS_CHILD=1
 test("wrapper marks github-copilot child run as a subagent child", async () => {
   const captured = await runWrapperWithFakePi("github-copilot/gpt-4o");
   assert.equal(captured.flags.PI_SUBAGENTS_CHILD, "1");
@@ -107,6 +103,12 @@ test("wrapper marks anthropic child run as a subagent child", async () => {
   assert.equal(captured.flags.PI_SUBAGENTS_CHILD, "1");
 });
 
+test("wrapper ignores stale tool and system prompt metadata", async () => {
+  const captured = await runWrapperWithFakePi("anthropic/claude-sonnet-4-5");
+  assert.equal(captured.flags.argv.includes("--tools"), false);
+  assert.equal(captured.flags.argv.includes("--append-system-prompt"), false);
+});
+
 test("wrapper marks github-copilot child runs as agent-initiated", async () => {
   const captured = await runWrapperWithFakePi("github-copilot/gpt-4o");
   assert.equal(captured.flags.PI_SUBAGENTS_GITHUB_COPILOT_INITIATOR, "agent");
@@ -115,25 +117,19 @@ test("wrapper marks github-copilot child runs as agent-initiated", async () => {
 
 test("wrapper leaves non-copilot child runs unchanged", async () => {
   const captured = await runWrapperWithFakePi("anthropic/claude-sonnet-4-5");
-  // The wrapper should not inject the copilot initiator for non-copilot models.
   assert.equal(captured.flags.PI_SUBAGENTS_GITHUB_COPILOT_INITIATOR, "");
   assert.equal(captured.flags.PI_SUBAGENTS_CHILD, "1");
 });
 
-// Regression test: ensure when requestedModel and resolvedModel differ, the
-// wrapper uses the same effective model for the child --model arg and the
-// copilot initiator env flag.
 test("wrapper uses effective model for both argv and env when requested/resolved differ", async () => {
   const requested = "anthropic/claude-sonnet-4-5";
   const resolved = "github-copilot/gpt-4o";
 
   const captured = await runWrapperWithFakePi(requested, resolved);
 
-  // The effective model should be the resolved model in this case.
   assert.equal(captured.flags.PI_SUBAGENTS_GITHUB_COPILOT_INITIATOR, "agent");
   assert.equal(captured.flags.PI_SUBAGENTS_CHILD, "1");
 
-  // Verify the child argv contains the effective model after a --model flag.
   const argv = captured.flags.argv;
   const modelIndex = argv.indexOf("--model");
   assert.ok(modelIndex >= 0, "expected --model in argv");
@@ -151,8 +147,6 @@ test("wrapper exits and writes result.json when the pi child cannot be spawned",
       {
         runId: "run-1",
         mode: "single",
-        agent: "scout",
-        agentSource: "builtin",
         task: "inspect auth",
         cwd: dir,
         requestedModel: "anthropic/claude-sonnet-4-5",
@@ -186,7 +180,8 @@ test("wrapper exits and writes result.json when the pi child cannot be spawned",
 
   const result = JSON.parse(await readFile(resultPath, "utf8"));
   assert.equal(result.runId, "run-1");
-  assert.equal(result.agent, "scout");
+  assert.equal(result.task, "inspect auth");
+  assert.equal("agent" in result, false);
   assert.equal(result.exitCode, 1);
   assert.match(result.errorMessage ?? "", /ENOENT|not found|spawn pi/i);
 });
@@ -217,8 +212,6 @@ test("wrapper does not exit early on non-terminal toolUse assistant messages", a
       {
         runId: "run-1",
         mode: "single",
-        agent: "scout",
-        agentSource: "builtin",
         task: "inspect auth",
         cwd: dir,
         requestedModel: "openai/gpt-5",
@@ -280,8 +273,6 @@ test("wrapper exits and writes result.json after terminal output even if the pi
       {
         runId: "run-1",
         mode: "single",
-        agent: "scout",
-        agentSource: "builtin",
         task: "inspect auth",
         cwd: dir,
         requestedModel: "openai/gpt-5",
@@ -341,8 +332,6 @@ test("wrapper still writes result.json when transcript/stdout artifact writes fa
       {
         runId: "run-1",
         mode: "single",
-        agent: "scout",
-        agentSource: "builtin",
         task: "inspect auth",
         cwd: dir,
         requestedModel: "openai/gpt-5",
diff --git a/src/wrapper/render.mjs b/src/wrapper/render.mjs
index d4eb9c8..b423fae 100644
--- a/src/wrapper/render.mjs
+++ b/src/wrapper/render.mjs
@@ -5,7 +5,6 @@ function shortenCommand(command) {
 export function renderHeader(meta) {
   return [
     "=== subagent ===",
-    `Agent: ${meta.agent}`,
     `Task: ${meta.task}`,
     `CWD: ${meta.cwd}`,
     `Requested model: ${meta.requestedModel ?? "(default)"}`,
diff --git a/src/wrapper/render.test.ts b/src/wrapper/render.test.ts
index 99a71e4..a4bec32 100644
--- a/src/wrapper/render.test.ts
+++ b/src/wrapper/render.test.ts
@@ -4,7 +4,6 @@ import { renderHeader, renderEventLine } from "./render.mjs";
 
 test("renderHeader prints generic subagent metadata", () => {
   const header = renderHeader({
-    agent: "scout",
     task: "Inspect authentication code",
     cwd: "/repo",
     requestedModel: "anthropic/claude-sonnet-4-5",
@@ -13,7 +12,7 @@ test("renderHeader prints generic subagent metadata", () => {
   });
 
   assert.match(header, /^=== subagent ===/m);
-  assert.match(header, /Agent: scout/);
+  assert.doesNotMatch(header, /Agent:/);
   assert.match(header, /Task: Inspect authentication code/);
   assert.match(header, /Session: \/repo\/\.pi\/subagents\/runs\/run-1\/child-session\.jsonl/);
 });