diff --git a/src/scribe/mcp/tools/rulebooks.py b/src/scribe/mcp/tools/rulebooks.py
index 43bd216..ee5da8e 100644
--- a/src/scribe/mcp/tools/rulebooks.py
+++ b/src/scribe/mcp/tools/rulebooks.py
@@ -297,6 +297,13 @@ async def create_rule(
     rulebook+topic ceremony). If it's a standard a CATEGORY of projects shares,
     put it in a themed subscribed rulebook, not the always-on one.
 
+    Write it general WITHOUT hedging for the exceptions. A project that needs
+    to strengthen, narrow or replace this rule writes its own and links it
+    with relate_rules(kind="overrides"), and one that adds local specifics
+    uses "elaborates" — so the general form does not have to anticipate every
+    project it will ever reach. A rulebook rule padded with "unless…" clauses
+    for two projects is two project rules that were never written.
+
     Before writing a rule at all, check whether another entity already models
     the thing. A rule is prose an agent must remember and apply; the others
     are structure a tool can resolve, render and check. Visual standards are a
@@ -412,12 +419,36 @@ async def create_project_rule(
         title: Short imperative title. If empty, derived from the first ~50
             characters of statement.
         when_to_apply: WHEN this rule fires — the trigger, not the
-            instruction. See create_rule; it decides the tier and it is how
-            the rule is found at the moment it matters.
-        tier: "always_on" (default) or "conditional" — see create_rule.
+            instruction, and the rule's retrieval surface: name the SYMPTOM,
+            the words someone would type while stuck. See create_rule for the
+            full argument. It informs the tier below rather than deciding it,
+            since a project rule's tier turns on area-scope, not on whether
+            the trigger can be named.
+        tier: "always_on" (default) or "conditional". The SAME two values as
+            create_rule, judged against a different cost — do not import that
+            tool's test wholesale. There, always_on means every session in
+            every project, so the bar is high: the trigger must be nameless
+            ("whenever you are working"). Here the rule is already scoped to
+            one project by construction, so always_on costs only that
+            project's sessions and the bar is correspondingly lower. A
+            project rule that names something specific is still ordinarily
+            always_on — being specific is what project rules are FOR.
+            Reach for conditional when the rule is about one AREA of a large
+            project — a CI quirk, a migration gotcha, one subsystem's
+            convention — so it arrives with that area instead of resident in
+            every session. The failure to avoid is local: forty always-on
+            rules on one project reproduces, inside that project, exactly the
+            preload bloat that made every rule compete for the same budget.
         system_ids: Ids from list_canonical_systems — the global AREAS this
-            rule is about.
-        arose_from_id: The note or task that CAUSED this rule.
+            rule is about. Worth setting even on a project rule: it is what
+            lets a conditional one surface when the project is working in
+            that area.
+        arose_from_id: The note or task that CAUSED this rule. Reach for it
+            harder here than on a rulebook rule — a project rule usually
+            comes from one traceable incident in this repo, where a family
+            rule is more often a standing preference with no single origin.
+            The link is what lets a later reader judge whether the incident
+            still describes the project.
         why: Optional rationale — the reason the rule exists.
         how_to_apply: Optional operationalization — when / where it kicks in.
         verify_with: How to check this rule is still true — see create_rule.