diff --git a/src/cli.ts b/src/cli.ts
index 00d9cbb..27a2c4c 100644
--- a/src/cli.ts
+++ b/src/cli.ts
@@ -17,10 +17,15 @@ const program = new Command();
 
 program
   .name('agentage')
-  .description('The agentage CLI')
+  .description('The offline-first terminal client for agentage Memory')
   .version(VERSION)
   .option('--no-daemon', 'run memory verbs in-process instead of via the daemon');
 
+program.addHelpText(
+  'after',
+  '\nNew here? Run: agentage vault add <name> --local, or agentage setup to connect an account.'
+);
+
 program.hook('preAction', () => {
   if (program.opts().daemon === false) disableDaemon();
 });
diff --git a/src/commands/memory.test.ts b/src/commands/memory.test.ts
index 05e9c74..2b92cc3 100644
--- a/src/commands/memory.test.ts
+++ b/src/commands/memory.test.ts
@@ -1,5 +1,6 @@
 import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
 import type { MemoryClient } from '../lib/memory-client.js';
+import { translateEngineMessage } from '../lib/memory-client.js';
 import { runDelete, runEdit, runList, runRead, runSearch, runWrite } from './memory.js';
 
 const client = (): MemoryClient => ({
@@ -110,4 +111,60 @@ describe('memory command wiring', () => {
     expect(c.delete).toHaveBeenCalledWith('a.md', { vault: undefined });
     expect(logs.join()).toContain('git history');
   });
+
+  it('edit with no --old/--new/--body errors instead of a silent no-op', async () => {
+    const c = client();
+    await expect(runEdit('a.md', {}, c)).rejects.toThrow(
+      'specify --old/--new for a replacement or --body to overwrite'
+    );
+    expect(c.edit).not.toHaveBeenCalled();
+  });
+
+  it('write rejects invalid --frontmatter JSON with a friendly hint', async () => {
+    const c = client();
+    await expect(runWrite('a.md', { body: 'x', frontmatter: '{bad' }, c)).rejects.toThrow(
+      /--frontmatter must be a JSON object, e\.g\. '\{"tags":\["x"\]\}'/
+    );
+    expect(c.write).not.toHaveBeenCalled();
+  });
+
+  it('write rejects non-object --frontmatter JSON (array/scalar)', async () => {
+    const c = client();
+    await expect(runWrite('a.md', { body: 'x', frontmatter: '[1,2]' }, c)).rejects.toThrow(
+      /must be a JSON object/
+    );
+    await expect(runWrite('a.md', { body: 'x', frontmatter: '42' }, c)).rejects.toThrow(
+      /must be a JSON object/
+    );
+    expect(c.write).not.toHaveBeenCalled();
+  });
+
+  it('write with no --body on a TTY errors instead of blocking on stdin', async () => {
+    const c = client();
+    const original = process.stdin.isTTY;
+    Object.defineProperty(process.stdin, 'isTTY', { value: true, configurable: true });
+    try {
+      await expect(runWrite('a.md', {}, c)).rejects.toThrow(
+        'provide --body, or pipe content on stdin'
+      );
+    } finally {
+      Object.defineProperty(process.stdin, 'isTTY', { value: original, configurable: true });
+    }
+    expect(c.write).not.toHaveBeenCalled();
+  });
+});
+
+describe('engine error translation', () => {
+  it('rewrites the memory__list MCP vocabulary to a CLI command', () => {
+    const engine =
+      'Unknown vault "@nosuchvault". Use memory__list with no folder to see available vaults.';
+    const out = translateEngineMessage(engine);
+    expect(out).not.toContain('memory__list');
+    expect(out).toContain('Run `agentage vault list` to see available vaults.');
+    expect(out).toContain('Unknown vault "@nosuchvault".');
+  });
+
+  it('passes through messages with no known engine pattern unchanged', () => {
+    expect(translateEngineMessage('not found: a.md')).toBe('not found: a.md');
+  });
 });
diff --git a/src/commands/memory.ts b/src/commands/memory.ts
index 015f89b..8800005 100644
--- a/src/commands/memory.ts
+++ b/src/commands/memory.ts
@@ -3,7 +3,11 @@ import { type Command } from 'commander';
 import { type TreeEntry } from '@agentage/memory-core';
 import { ensureDaemon } from '../lib/daemon-client.js';
 import { daemonDisabled } from '../lib/daemon-pref.js';
-import { createDirectClient, type MemoryClient } from '../lib/memory-client.js';
+import {
+  createDirectClient,
+  translateEngineMessage,
+  type MemoryClient,
+} from '../lib/memory-client.js';
 import { loadVaultsConfig } from '../lib/vaults.js';
 
 // Default engine path (DO3/DO4): the daemon - single writer, autostarted - when reachable; the
@@ -21,6 +25,21 @@ const readStdin = async (): Promise<string> => {
   return Buffer.concat(chunks).toString('utf-8');
 };
 
+// --frontmatter must be a JSON object; a raw parser error or a non-object value is unfriendly.
+const parseFrontmatter = (raw?: string): Record<string, unknown> | undefined => {
+  if (!raw) return undefined;
+  let parsed: unknown;
+  try {
+    parsed = JSON.parse(raw);
+  } catch (err) {
+    const detail = err instanceof Error ? err.message : String(err);
+    throw new Error(`--frontmatter must be a JSON object, e.g. '{"tags":["x"]}': ${detail}`);
+  }
+  if (typeof parsed !== 'object' || parsed === null || Array.isArray(parsed))
+    throw new Error(`--frontmatter must be a JSON object, e.g. '{"tags":["x"]}'`);
+  return parsed as Record<string, unknown>;
+};
+
 const emit = (json: boolean, data: unknown, human: () => void): void => {
   if (json) console.log(JSON.stringify(data, null, 2));
   else human();
@@ -67,10 +86,11 @@ export const runWrite = async (
   client?: MemoryClient
 ): Promise<void> => {
   const c = client ?? (await resolveClient());
-  const body = opts.body !== undefined && opts.body !== '-' ? opts.body : await readStdin();
-  const frontmatter = opts.frontmatter
-    ? (JSON.parse(opts.frontmatter) as Record<string, unknown>)
-    : undefined;
+  const inlineBody = opts.body !== undefined && opts.body !== '-';
+  if (!inlineBody && process.stdin.isTTY)
+    throw new Error('provide --body, or pipe content on stdin');
+  const body = inlineBody ? opts.body! : await readStdin();
+  const frontmatter = parseFrontmatter(opts.frontmatter);
   const out = await c.write(ref, body, { vault: opts.vault, frontmatter });
   emit(opts.json ?? false, out, () => console.log(chalk.green(`Wrote ${out.path}`)));
 };
@@ -81,6 +101,8 @@ export const runEdit = async (
   client?: MemoryClient
 ): Promise<void> => {
   const c = client ?? (await resolveClient());
+  if (opts.old === undefined && opts.body === undefined)
+    throw new Error('specify --old/--new for a replacement or --body to overwrite');
   const op =
     opts.old !== undefined
       ? { mode: 'str_replace' as const, old_str: opts.old, new_str: opts.new ?? '' }
@@ -117,7 +139,8 @@ export const runDelete = async (
 
 const guard = (fn: () => Promise<void>): Promise<void> =>
   fn().catch((err: unknown) => {
-    console.error(chalk.red(err instanceof Error ? err.message : String(err)));
+    const message = translateEngineMessage(err instanceof Error ? err.message : String(err));
+    console.error(chalk.red(message));
     process.exitCode = 1;
   });
 
diff --git a/src/commands/vault.ts b/src/commands/vault.ts
index ce3b7c7..5abc2d9 100644
--- a/src/commands/vault.ts
+++ b/src/commands/vault.ts
@@ -112,7 +112,7 @@ export const runVaultList = (opts: { json?: boolean }, deps: VaultDeps = default
     return;
   }
   if (names.length === 0) {
-    deps.log('No vaults registered. Add one with `agentage vault add <name>`.');
+    deps.log('No vaults registered. Add one with `agentage vault add <name> --local`.');
     return;
   }
   for (const name of names) {
diff --git a/src/lib/file-lock.test.ts b/src/lib/file-lock.test.ts
index 005b955..49922a1 100644
--- a/src/lib/file-lock.test.ts
+++ b/src/lib/file-lock.test.ts
@@ -1,5 +1,13 @@
 import { execFile } from 'node:child_process';
-import { existsSync, mkdirSync, mkdtempSync, readFileSync, rmSync, writeFileSync } from 'node:fs';
+import {
+  chmodSync,
+  existsSync,
+  mkdirSync,
+  mkdtempSync,
+  readFileSync,
+  rmSync,
+  writeFileSync,
+} from 'node:fs';
 import { tmpdir } from 'node:os';
 import { join } from 'node:path';
 import { pathToFileURL } from 'node:url';
@@ -42,6 +50,41 @@ describe('file lock', () => {
     releaseFileLock(target);
   });
 
+  // chmod-based unwritability does not apply to root, so skip these there.
+  const asRoot = typeof process.getuid === 'function' && process.getuid() === 0;
+
+  it.skipIf(asRoot)('fails fast on a permission error instead of treating it as contention', () => {
+    // An unwritable lock dir: writeFileSync({flag:'wx'}) throws EACCES/EPERM, which never clears.
+    const roDir = join(dir, 'readonly');
+    mkdirSync(roDir);
+    const roTarget = join(roDir, 'data.json');
+    chmodSync(roDir, 0o500);
+    try {
+      expect(() => acquireFileLock(roTarget)).toThrow(/permission denied/);
+    } finally {
+      chmodSync(roDir, 0o700);
+    }
+  });
+
+  it.skipIf(asRoot)(
+    'withFileLock surfaces a permission error immediately, never spinning MAX_WAIT_MS',
+    async () => {
+      const roDir = join(dir, 'readonly2');
+      mkdirSync(roDir);
+      const roTarget = join(roDir, 'data.json');
+      chmodSync(roDir, 0o500);
+      const started = Date.now();
+      try {
+        await expect(withFileLock(roTarget, () => 'unreachable')).rejects.toThrow(
+          /permission denied/
+        );
+        expect(Date.now() - started).toBeLessThan(2_000);
+      } finally {
+        chmodSync(roDir, 0o700);
+      }
+    }
+  );
+
   it('releases idempotently', () => {
     acquireFileLock(target);
     releaseFileLock(target);
diff --git a/src/lib/file-lock.ts b/src/lib/file-lock.ts
index 465ca4a..da398a4 100644
--- a/src/lib/file-lock.ts
+++ b/src/lib/file-lock.ts
@@ -64,7 +64,18 @@ export const acquireFileLock = (target: string, now: number = Date.now()): boole
     try {
       writeFileSync(lockPath(target), `${process.pid} ${now}`, { flag: 'wx' });
       return true;
-    } catch {
+    } catch (err) {
+      // Only EEXIST means contention. A permission/read-only error never clears, so failing fast
+      // beats burning the full MAX_WAIT_MS before reporting a generic "could not acquire lock".
+      const code = (err as NodeJS.ErrnoException).code;
+      if (code !== 'EEXIST') {
+        const path = lockPath(target);
+        throw new Error(
+          code === 'EACCES' || code === 'EPERM' || code === 'EROFS'
+            ? `permission denied: ${path}`
+            : `could not write lock file ${path}${code ? ` (${code})` : ''}`
+        );
+      }
       const held = heldAt(lockPath(target));
       if (held !== null && now - held < LOCK_TTL_MS) return false;
       if (!takeOverStale(target, now)) return false;
diff --git a/src/lib/memory-client.ts b/src/lib/memory-client.ts
index 35a139b..7dc3d73 100644
--- a/src/lib/memory-client.ts
+++ b/src/lib/memory-client.ts
@@ -19,6 +19,21 @@ export interface DeleteResult {
   deleted: boolean;
 }
 
+// Engine (memory-core) messages leak MCP tool vocabulary (`memory__list`, ...) unfit for a terminal.
+// Rewrite the known patterns to CLI vocabulary at this seam; do not fork the engine.
+const ENGINE_MESSAGE_MAP: ReadonlyArray<readonly [RegExp, string]> = [
+  [
+    /Use memory__list with no folder to see available vaults\.?/g,
+    'Run `agentage vault list` to see available vaults.',
+  ],
+];
+
+export const translateEngineMessage = (message: string): string =>
+  ENGINE_MESSAGE_MAP.reduce(
+    (m, [pattern, replacement]) => m.replace(pattern, replacement),
+    message
+  );
+
 export interface VerbOptions {
   vault?: string;
 }