diff --git a/docs/product/output-conventions.md b/docs/product/output-conventions.md
index d10a552e..9a059653 100644
--- a/docs/product/output-conventions.md
+++ b/docs/product/output-conventions.md
@@ -103,7 +103,18 @@ The CLI prints one advisory line after normal command output when the agent skil
 Prisma agent skills are out of date (installed @prisma/orm-postgres 8.1.0, synced 8.0.0). Run: prisma skills sync
 ```
 
-A project that has never been synced is reported the same way, with `synced none`. Like the update notification, this is human-oriented stderr output, must never reach stdout, and must never change the command's exit code. Unlike the update notification it is **not** conditioned on a TTY: its main reader is a coding agent, which runs the CLI without one.
+A project that has never been synced is reported the same way, with `synced none`. Like the update notification, this is human-oriented stderr output and must never change the command's exit code. Unlike the update notification it is **not** conditioned on a TTY: its main reader is a coding agent, which runs the CLI without one.
+
+Under `--format markdown` the notice goes to stdout instead, because that format promises the whole run on one stream. It is the last section of the document, separated from the command's output by a blank line:
+
+```markdown
+
+### Notice
+Prisma agent skills are out of date (installed @prisma/orm-postgres 8.1.0, synced 8.0.0).
+- Sync agent skills: `prisma skills sync`
+```
+
+Under every other format the notice is stderr output and must never reach stdout.
 
 It is silent when:
 
@@ -473,7 +484,7 @@ Rules:
 
 ## `--format markdown`
 
-`--format markdown` renders the same blocks a command describes for human output as plain Markdown: a summary line, `label: value` rows, GFM pipe tables, bullet lists, nested bullets for trees, and fenced code for drawings, followed by `### Next` for the suggested next actions and `### Diagnostics` for any findings. It exists for an agent that reads CLI output as text rather than parsing JSON: every value is labelled, nothing is padded, wrapped, aligned, or coloured, and no tokens go to envelope keys. Every part of the run's output — blocks, next actions, diagnostics, structured errors, help, `--version`, and live events — lands on stdout, and the engine writes nothing to stderr. The format is only ever explicit: without `--format markdown` a terminal gets human output and a pipe gets JSON.
+`--format markdown` renders the same blocks a command describes for human output as plain Markdown: a summary line, `label: value` rows, GFM pipe tables, bullet lists, nested bullets for trees, and fenced code for drawings, followed by `### Next` for the suggested next actions and `### Diagnostics` for any findings. It exists for an agent that reads CLI output as text rather than parsing JSON: every value is labelled, nothing is padded, wrapped, aligned, or coloured, and no tokens go to envelope keys. Every part of the run's output — blocks, next actions, diagnostics, structured errors, help, `--version`, and live events — lands on stdout, and the engine writes nothing to stderr. The out-of-date agent skills notice follows the same rule: under this format it is a trailing `### Notice` section on stdout rather than a stderr line. The format is only ever explicit: without `--format markdown` a terminal gets human output and a pipe gets JSON.
 
 ## Non-Streaming JSON Shape
 
diff --git a/packages/cli/src/main.ts b/packages/cli/src/main.ts
index 4fa68c91..a8121649 100644
--- a/packages/cli/src/main.ts
+++ b/packages/cli/src/main.ts
@@ -42,6 +42,7 @@ export async function main(
     env: proc.env,
     argv: proc.argv.slice(2),
     cwd: proc.cwd(),
+    stdout: proc.stdout,
     stderr: proc.stderr,
   });
   return exitCode;
diff --git a/packages/cli/src/skills-check.ts b/packages/cli/src/skills-check.ts
index 2b57f497..b7ad239c 100644
--- a/packages/cli/src/skills-check.ts
+++ b/packages/cli/src/skills-check.ts
@@ -3,10 +3,15 @@
  * that ship inside the Prisma packages a project installs, so they go
  * out of date whenever those packages move and nothing re-copies them.
  * The project's postinstall normally does; this catches every way that
- * can be bypassed, by naming the mismatch once on stderr.
+ * can be bypassed, by naming the mismatch once.
  *
- * It never changes the exit code, never writes to stdout, and is not
- * conditioned on a TTY: agents run without one and are who this is for.
+ * It goes to stderr, except under `--format markdown`, which promises
+ * that everything the command produces arrives on stdout as one
+ * Markdown document; there the notice is a trailing `### Notice`
+ * section on stdout instead.
+ *
+ * It never changes the exit code and is not conditioned on a TTY:
+ * agents run without one and are who this is for.
  */
 import { detectCI } from "@prisma/cli-engine";
 import { readProjectSkillsConfig } from "./commands/skills/config";
@@ -23,6 +28,7 @@ export interface SkillsCheckRuntime {
   readonly env: NodeJS.ProcessEnv;
   readonly argv: readonly string[];
   readonly cwd: string;
+  readonly stdout: { write(text: string): unknown };
   readonly stderr: { write(text: string): unknown };
 }
 
@@ -69,6 +75,13 @@ export async function maybeWriteSkillsStaleNotice(
       return;
     }
     const dirs = agentSkillDirs(agents);
+    if (isFormat(flagTokens(runtime.argv), "markdown")) {
+      const notice = renderStaleNoticeMarkdown(status, dirs);
+      if (notice !== null) {
+        runtime.stdout.write(notice);
+      }
+      return;
+    }
     const notice = renderStaleNotice(status, dirs);
     if (notice !== null) {
       runtime.stderr.write(notice);
@@ -97,7 +110,8 @@ function firstOutdatedSkillIn(
   );
 }
 
-export function renderStaleNotice(
+/** The mismatch in words, without the stream's framing around it. */
+function staleNoticeSentence(
   status: SkillsStatus,
   dirs: readonly string[],
 ): string | null {
@@ -111,11 +125,33 @@ export function renderStaleNotice(
   )?.syncedVersion;
   return (
     `Prisma agent skills are out of date (installed ${outdated.library} ` +
-    `${outdated.version}, synced ${synced ?? "none"}). ` +
-    `Run: ${getCliName()} skills sync\n`
+    `${outdated.version}, synced ${synced ?? "none"})`
   );
 }
 
+export function renderStaleNotice(
+  status: SkillsStatus,
+  dirs: readonly string[],
+): string | null {
+  const sentence = staleNoticeSentence(status, dirs);
+  return sentence === null
+    ? null
+    : `${sentence}. Run: ${getCliName()} skills sync\n`;
+}
+
+/** The same notice as a trailing section of the Markdown document, in
+ *  the heading-then-bullet shape the engine renders `### Diagnostics`
+ *  in. The leading blank line separates it from the command's output. */
+export function renderStaleNoticeMarkdown(
+  status: SkillsStatus,
+  dirs: readonly string[],
+): string | null {
+  const sentence = staleNoticeSentence(status, dirs);
+  return sentence === null
+    ? null
+    : `\n### Notice\n${sentence}.\n- Sync agent skills: \`${getCliName()} skills sync\`\n`;
+}
+
 /** The shared flags that take a separate value, so the word after them
  *  is that value rather than the command being invoked. */
 const FLAGS_TAKING_A_VALUE = new Set([
@@ -176,10 +212,14 @@ function isSuppressedByInvocation(runtime: SkillsCheckRuntime): boolean {
   if (argv.includes("--version")) {
     return true;
   }
-  return argv.some(
+  return isFormat(argv, "json");
+}
+
+function isFormat(tokens: readonly string[], format: string): boolean {
+  return tokens.some(
     (token, index) =>
-      token === "--format=json" ||
-      (token === "--format" && argv[index + 1] === "json"),
+      token === `--format=${format}` ||
+      (token === "--format" && tokens[index + 1] === format),
   );
 }
 
diff --git a/packages/cli/tests/skills-check.test.ts b/packages/cli/tests/skills-check.test.ts
index 90d3917f..fe9281a2 100644
--- a/packages/cli/tests/skills-check.test.ts
+++ b/packages/cli/tests/skills-check.test.ts
@@ -1,7 +1,8 @@
 // biome-ignore-all lint/performance/noAwaitInLoops: the fixture writes one harness directory after another.
 /**
- * The staleness check as the bin runs it: one stderr line after the
- * command's own output, never touching the exit code, and silent
+ * The staleness check as the bin runs it: one line after the command's
+ * own output — on stderr, or on stdout as a Markdown section under
+ * `--format markdown` — never touching the exit code, and silent
  * through every off switch.
  */
 import { existsSync } from "node:fs";
@@ -95,6 +96,20 @@ function stubCli(exitCode = 0, marker?: string) {
   });
 }
 
+/** What a command writes under --format markdown: its document on
+ *  stdout and nothing on stderr. */
+function stubMarkdownCli(document: string, exitCode = 0) {
+  return () => ({
+    run: async (
+      _argv: readonly string[],
+      runtime: { stdout: { write(text: string): void } },
+    ) => {
+      runtime.stdout.write(document);
+      return exitCode;
+    },
+  });
+}
+
 /** A project whose installed package is newer than the copies in its
  *  harness directories. */
 async function makeStaleProject(): Promise<string> {
@@ -229,6 +244,99 @@ describe("the skills check", () => {
   });
 });
 
+describe("the skills check under --format markdown", () => {
+  const MARKDOWN_NOTICE =
+    "\n### Notice\n" +
+    "Prisma agent skills are out of date (installed @prisma/orm-postgres 8.1.0, synced 8.0.0).\n" +
+    "- Sync agent skills: `prisma skills sync`\n";
+
+  it.each([
+    ["--format markdown", ["auth", "whoami", "--format", "markdown"]],
+    ["--format=markdown", ["auth", "whoami", "--format=markdown"]],
+  ])("writes the notice to stdout under %s", async (_name, argv) => {
+    const proc = makeProcess({ cwd: await makeStaleProject(), argv });
+
+    const exitCode = await main(
+      proc,
+      stubMarkdownCli("[ok] Signed in as ada@example.com\n"),
+    );
+
+    expect(exitCode).toBe(0);
+    expect(proc.stdoutText).toBe(
+      `[ok] Signed in as ada@example.com\n${MARKDOWN_NOTICE}`,
+    );
+    expect(proc.stderrText).toBe("");
+  });
+
+  it("reports a project that was never synced the same way", async () => {
+    const root = await makeProjectRoot("check-");
+    await installPackage(root, {
+      name: "@prisma/orm-postgres",
+      version: "8.1.0",
+      skills: ["prisma-8"],
+    });
+    const proc = makeProcess({
+      cwd: root,
+      argv: ["auth", "whoami", "--format", "markdown"],
+    });
+
+    await main(proc, stubMarkdownCli(""));
+
+    expect(proc.stdoutText).toContain(
+      "(installed @prisma/orm-postgres 8.1.0, synced none)",
+    );
+    expect(proc.stderrText).toBe("");
+  });
+
+  it("says nothing on either stream when every copy is current", async () => {
+    const proc = makeProcess({
+      cwd: await makeSyncedProject(),
+      argv: ["auth", "whoami", "--format", "markdown"],
+    });
+
+    await main(proc, stubMarkdownCli(""));
+
+    expect(proc.stdoutText).toBe("");
+    expect(proc.stderrText).toBe("");
+  });
+
+  it("leaves the exit code of a failing command alone", async () => {
+    const proc = makeProcess({
+      cwd: await makeStaleProject(),
+      argv: ["auth", "whoami", "--format", "markdown"],
+    });
+
+    const exitCode = await main(proc, stubMarkdownCli("", 2));
+
+    expect(exitCode).toBe(2);
+    expect(proc.stdoutText).toBe(MARKDOWN_NOTICE);
+  });
+
+  it("stays on stderr when --format names another value", async () => {
+    const proc = makeProcess({
+      cwd: await makeStaleProject(),
+      argv: ["auth", "whoami", "--format", "human"],
+    });
+
+    await main(proc, stubCli());
+
+    expect(proc.stdoutText).toBe("");
+    expect(proc.stderrText).toContain(NOTICE);
+  });
+
+  it("ignores a markdown format after a bare --", async () => {
+    const proc = makeProcess({
+      cwd: await makeStaleProject(),
+      argv: ["auth", "whoami", "--", "--format", "markdown"],
+    });
+
+    await main(proc, stubCli());
+
+    expect(proc.stdoutText).toBe("");
+    expect(proc.stderrText).toContain(NOTICE);
+  });
+});
+
 describe("the skills check off switches", () => {
   it.each([
     ["--quiet", { argv: ["auth", "whoami", "--quiet"] }],
@@ -250,6 +358,7 @@ describe("the skills check off switches", () => {
     await main(proc, stubCli());
 
     expect(proc.stderrText).toBe("");
+    expect(proc.stdoutText).toBe("");
   });
 
   it.each([