diff --git a/src/pf1e_simulator/abilities.py b/src/pf1e_simulator/abilities.py
index 6b2acdc..3849dd5 100644
--- a/src/pf1e_simulator/abilities.py
+++ b/src/pf1e_simulator/abilities.py
@@ -397,8 +397,15 @@ BITTER = AbilitySpec(
     source_detail="drawback: ally healing received reduced by 1 (engine behavior)",
 )
 
-# Ambitious: +1 trait bonus on one Craft or Profession skill
-AMBITIOUS = AbilitySpec(name="Ambitious", category="trait")
+# Ambitious (Basic Social trait, APG): "+4 trait bonus on Diplomacy checks
+# made to influence creatures with at least 5 Hit Dice more than you
+# possess." The HD-differential gate on a social skill the engine never
+# resolves is not expressible -> documented traced no-op.
+AMBITIOUS = AbilitySpec(
+    name="Ambitious",
+    category="trait",
+    source_detail="trait (not modeled: +4 Diplomacy vs creatures 5+ HD greater)",
+)
 
 # Rapid Reload: reload firearms as free action
 RAPID_RELOAD = AbilitySpec(name="Rapid Reload (Pistol)", category="feat")
@@ -449,12 +456,24 @@ LONELY = AbilitySpec(
     ),
 )
 
-# Larger Than Life: +1 trait bonus on Intimidate
+# Larger Than Life (Basic Combat trait, APG): "When you use the Intimidate
+# skill on a creature while wielding a firearm, you are considered one size
+# category larger than your actual size." Intimidate is never resolved by the
+# engine and size-for-skill is not modeled -> documented traced no-op (the
+# previous flat "+1 intimidate" was the wrong effect: the trait grants no
+# numeric bonus and only applies while wielding a firearm).
 LARGER_THAN_LIFE = AbilitySpec(
     name="Larger Than Life",
     category="trait",
-    effects=(StatModifier(target="intimidate", value=1),),
+    source_detail="trait (not modeled: one size larger for Intimidate with a firearm)",
 )
 
-# Focused Study: +2 on one skill
-FOCUSED_STUDY = AbilitySpec(name="Focused Study", category="trait")
+# Focused Study (human alternate racial trait, ARG): "+2 trait bonus on one
+# skill" (chosen at 1st level, re-chosen at 8th/16th). The chosen skill is a
+# social/exploration skill the combat engine never resolves -> documented
+# traced no-op.
+FOCUSED_STUDY = AbilitySpec(
+    name="Focused Study",
+    category="trait",
+    source_detail="trait (not modeled: +2 on one chosen skill, social/exploration)",
+)