diff --git a/src/onboarding/buddy_persona.py b/src/onboarding/buddy_persona.py
index 28c6ccf..7c54bf5 100644
--- a/src/onboarding/buddy_persona.py
+++ b/src/onboarding/buddy_persona.py
@@ -149,6 +149,31 @@
     "later, so never call it a score, a result, or final.\n"
 )
 
+# Both halves are the point. The first is routing: "how do I create a project?" is
+# a question about *this app*, and the corpus -- the project's own material -- has
+# never heard of its pages, so a mentor that searches it either says nothing or
+# describes a screen that does not exist. The second is the constraint that makes
+# the answer safe: the guide is filtered for the reader, so a page it does not list
+# is one their sidebar does not have, and sending them there is a dead end.
+#
+# Shared by both personas: a manager asks where things are at least as often as a
+# hire does, and nothing in it presumes which of the two is reading.
+_APP_GUIDE_CLAUSE = (
+    "- Questions about this app itself -- where a page or button is, how to do "
+    "something here (create a project, set up or choose a role, connect a source, "
+    "write arrival steps), what the page they are on is for -- are answered by "
+    "`get_app_guide`, never by `search_docs`: the docs describe the project the team "
+    "works on, not this app. Call it before answering, even when you think you know, "
+    'and read "this page" or "here" as the page it says they are looking at.\n'
+    "- Describe only the pages and buttons the guide names, in its words, and link a "
+    "page as a Markdown link to its path, like [Board](/board) -- or, where the guide "
+    "gives a how-to its own link, to that one, which opens the right tab. "
+    "Buttons on the app's own pages are not the chat buttons your tools make: naming "
+    "the ones the guide names is fine. "
+    "Never send somebody to a page the guide does not list as theirs to open: when it "
+    "says somebody else does it, say who to ask.\n"
+)
+
 # The onboarding-path clauses. The first is mounted on the *read* tool rather than on
 # the actions: a mentor that knows the path exists should talk about it even where it
 # may not touch it, and the backend mounts that read only for a hire who has a path.
@@ -536,6 +561,10 @@ def build_persona(
             f"process works, and the hire-state tools ({rendered}) for the hire's "
             "own progress.\n"
         )
+    # Straight after the routing rule above, which it narrows: "how this product
+    # works" reads as including the app, and it does not.
+    if "get_app_guide" in available:
+        parts.append(_APP_GUIDE_CLAUSE)
 
     # After the list above, which it narrows: that clause sorts tools by subject, and
     # "what should I work on" belongs to no subject cleanly enough to be routed by it.
@@ -600,6 +629,8 @@ def _team_persona(available: set[str], capabilities_enabled: bool) -> str:
             "`search_docs` for how the project itself works. A member id the tools "
             "give you is how you name somebody; never guess one.\n"
         )
+    if "get_app_guide" in available:
+        parts.append(_APP_GUIDE_CLAUSE)
     parts.append(_TEAM_FACTS_CLAUSE)
     if "open_area" in available:
         parts.append(_TEAM_AREA_CLAUSE)
diff --git a/tests/onboarding/test_buddy_persona.py b/tests/onboarding/test_buddy_persona.py
index af3349c..fec30f2 100644
--- a/tests/onboarding/test_buddy_persona.py
+++ b/tests/onboarding/test_buddy_persona.py
@@ -694,3 +694,50 @@ def test_search_only_names_grep_only_when_it_is_mounted() -> None:
     assert "`grep` for an exact name" in with_grep
     assert "`grep` for an exact name" in team
     assert "grep" not in without
+
+
+def test_app_questions_are_routed_to_the_guide_not_the_corpus() -> None:
+    """The corpus is the project's material; it has never heard of this app's pages."""
+    persona = build_persona([*_ALL_TOOLS, "get_app_guide"])
+
+    assert "`get_app_guide`, never by `search_docs`" in persona
+    assert "create a project" in persona
+
+
+def test_the_guide_rule_forbids_sending_somebody_to_a_page_they_cannot_open() -> None:
+    persona = build_persona([*_ALL_TOOLS, "get_app_guide"])
+
+    assert "Never send somebody to a page the guide does not list" in persona
+    assert "say who to ask" in persona
+    # Root-relative, so the chat opens it in place rather than in a new tab. A page
+    # everybody can open: an example is a temptation, so it must never be a dead end.
+    assert "[Board](/board)" in persona
+    # A how-to's own link opens the tab the steps talk about.
+    assert "gives a how-to its own link, to that one" in persona
+
+
+def test_the_guide_rule_frees_the_app_buttons_from_the_no_button_rule() -> None:
+    """'Never describe a button' is about chat proposals, not the app's own pages."""
+    persona = build_persona([*_ALL_TOOLS, "get_app_guide"])
+
+    assert "Never describe a button instead of making one" in persona
+    assert "not the chat buttons your tools make" in persona
+
+
+def test_the_guide_rule_follows_the_routing_rule_it_narrows() -> None:
+    """'How this product works' reads as including the app; the next rule says not."""
+    persona = build_persona([*_ALL_TOOLS, "get_app_guide"])
+
+    routing = persona.index("hire-state tools")
+    assert routing < persona.index("`get_app_guide`, never by")
+
+
+def test_the_guide_rule_is_absent_without_the_tool() -> None:
+    assert "get_app_guide" not in build_persona(_ALL_TOOLS)
+    assert "get_app_guide" not in build_persona(_TEAM_TOOLS, team_mode=True)
+
+
+def test_a_manager_is_given_the_guide_rule_too() -> None:
+    persona = build_persona([*_TEAM_TOOLS, "get_app_guide"], team_mode=True)
+
+    assert "`get_app_guide`, never by `search_docs`" in persona