diff --git a/backend/app/tasks/quiz_tasks.py b/backend/app/tasks/quiz_tasks.py
index b1843dd..c4ad423 100644
--- a/backend/app/tasks/quiz_tasks.py
+++ b/backend/app/tasks/quiz_tasks.py
@@ -1,6 +1,7 @@
 """Async quiz extraction task with step-by-step progress reporting via Redis."""
 import json
 import logging
+import re
 import time
 import os
 
@@ -954,6 +955,25 @@ class ArticleDraftError(RuntimeError):
     """A refusal with a sentence the educator can act on."""
 
 
+def _why(exc: Exception) -> str:
+    """One sentence a person can act on, out of whatever the provider said.
+
+    A proxy answers a missing model with three hundred characters of JSON. The
+    part that matters is which model, and that it does not exist — everything
+    else belongs in the log.
+    """
+    text = str(exc)
+    found = re.search(r"Invalid model name passed in model=([\w.:-]+)", text)
+    if found:
+        return (f"The model configured for this job — {found.group(1)} — is not on "
+                "the AI proxy any more. Pick another in Admin → Models.")
+    if "429" in text or "rate limit" in text.lower():
+        return "The AI provider is rate-limiting us. Try again in a minute."
+    if "timed out" in text.lower() or "timeout" in text.lower():
+        return "The model took too long to answer."
+    return text[:160]
+
+
 def _draft_grounding(r, job_id: str, topic: str, use_library: bool, use_pubmed: bool):
     """Source material for a draft, and the references that come with it.
 
@@ -1221,6 +1241,10 @@ def generate_article_cards(self, job_id: str, user_id: int, article_id: int,
         db.rollback()
         r.set(f"extraction:status:{job_id}", "failed", ex=EXPIRE_SECONDS)
         r.set(f"extraction:error:{job_id}", str(exc)[:300], ex=EXPIRE_SECONDS)
-        _push_step(r, job_id, "error", "Card generation failed.")
+        # The reason, on the line somebody actually reads. "Card generation
+        # failed." was all the jobs panel showed for a fortnight while the
+        # answer — a model the proxy had dropped — sat in a field nothing
+        # displayed.
+        _push_step(r, job_id, "error", f"Card generation failed. {_why(exc)}")
     finally:
         db.close()
diff --git a/frontend/src/components/ArticleReader.jsx b/frontend/src/components/ArticleReader.jsx
index 37a3eba..4b1fdab 100644
--- a/frontend/src/components/ArticleReader.jsx
+++ b/frontend/src/components/ArticleReader.jsx
@@ -1,4 +1,9 @@
 import { useEffect, useRef, useState } from 'react'
+// The reader carries its own appearance. These rules lived only in
+// ArticlesPage.css, so the reader rendered correctly on the reading page and
+// as unstyled boxes anywhere else it was used — the split pane inside AI Mode
+// being where that finally showed.
+import '../pages/ArticlesPage.css'
 import useMediaQuery from '../hooks/useMediaQuery'
 import useHeaderOffset from '../hooks/useHeaderOffset'
 import { useSessionDrawer } from '../context/SessionDrawer'
diff --git a/frontend/src/pages/AiModePage.css b/frontend/src/pages/AiModePage.css
index 2b5ca2d..5293fbe 100644
--- a/frontend/src/pages/AiModePage.css
+++ b/frontend/src/pages/AiModePage.css
@@ -1,6 +1,8 @@
 /* AI Mode: a rail of threads beside the conversation. */
 
-.ai-page { display: grid; grid-template-columns: 250px 1fr; gap: 18px; align-items: start; max-width: 1060px; margin: 0 auto; }
+/* A little air under the composer. It sat flush against the footer, so the
+   box you type into looked like part of the site's furniture. */
+.ai-page { display: grid; grid-template-columns: 250px 1fr; gap: 18px; align-items: start; max-width: 1060px; margin: 0 auto; padding-bottom: 28px; }
 /* Folded, the rail keeps only its two controls, and the conversation takes the
    width back rather than leaving a column of nothing beside it. */
 .ai-page.is-folded { grid-template-columns: 52px 1fr; }
diff --git a/frontend/src/pages/CategoriesPage.jsx b/frontend/src/pages/CategoriesPage.jsx
index 1acab9e..3710c07 100644
--- a/frontend/src/pages/CategoriesPage.jsx
+++ b/frontend/src/pages/CategoriesPage.jsx
@@ -383,7 +383,10 @@ export default function CategoriesPage() {
 
   return (
     <div className="cat-page">
-      <BackLink to="/settings?s=tools">Tools</BackLink>
+      {/* Back to the questions, because that is what a taxonomy is for and
+          where everybody arrives from. It used to lead to Tools, which is a
+          settings page nobody was on. */}
+      <BackLink to="/questions/manage">Questions</BackLink>
       <div className="cat-header">
         <div>
           <h1>Taxonomy</h1>
diff --git a/frontend/src/pages/QuestionManagerPage.jsx b/frontend/src/pages/QuestionManagerPage.jsx
index 07ba80a..8274d26 100644
--- a/frontend/src/pages/QuestionManagerPage.jsx
+++ b/frontend/src/pages/QuestionManagerPage.jsx
@@ -174,6 +174,10 @@ export default function QuestionManagerPage() {
         </div>
         <div className="qm-header-actions">
           <Link className="btn btn-secondary" to="/categories">Taxonomy</Link>
+          {/* The workbench is question work and lives beside the questions. It
+              was listed under Settings → Tools, which is a place nobody is
+              when they are thinking about a PDF full of questions. */}
+          <Link className="btn btn-secondary" to="/tools">Workbench</Link>
           <QuestionImport onImported={refresh} selectedIds={selected} />
           <Link className="btn btn-primary" to="/questions/new"
             state={{ from: '/questions/manage', label: 'Questions' }}>+ New question</Link>
diff --git a/frontend/src/pages/SettingsPage.jsx b/frontend/src/pages/SettingsPage.jsx
index 16c2453..b35b34c 100644
--- a/frontend/src/pages/SettingsPage.jsx
+++ b/frontend/src/pages/SettingsPage.jsx
@@ -247,8 +247,10 @@ function ToolsSection() {
       <div className="set-cards">
         {[
           { to: '/handbook', icon: '📖', label: 'Handbook', desc: 'How the parts that are not obvious work' },
-          { to: '/tools', icon: '🧪', label: 'Question workbench', desc: 'PDFs in, drafts read, questions out' },
-          { to: '/categories', icon: '🗂️', label: 'Taxonomy', desc: 'Topics, systems, symptoms, diseases' },
+          /* Not the workbench and not the taxonomy. Both are question work,
+             both are one press from Questions in the main menu, and listing
+             them here as well is a second door into the same room — which is
+             how somebody ends up in Settings wondering how to get back. */
           { to: '/access', icon: '🔑', label: 'Access', desc: 'Who may edit what' },
           { to: '/trash', icon: '🗑️', label: 'Trash', desc: 'Restore deleted questions' },
           { to: '/jobs', icon: '📋', label: 'Extraction jobs', desc: 'Extraction history' },
diff --git a/frontend/src/pages/ToolsPage.jsx b/frontend/src/pages/ToolsPage.jsx
index cb9066c..aea8ec1 100644
--- a/frontend/src/pages/ToolsPage.jsx
+++ b/frontend/src/pages/ToolsPage.jsx
@@ -56,7 +56,7 @@ export default function ToolsPage() {
         {/* The way back. This page is a workbench rather than part of the
             study flow, and without a trail out of it you are somewhere that
             looks like a different application. */}
-        <BackLink to="/settings?s=tools">Tools in Settings</BackLink>
+        <BackLink to="/questions/manage">Questions</BackLink>
         <h1>Tools</h1>
         <p>
           A document goes in, a model proposes questions, you read them, and the