diff --git a/packages/entity/index.hooks.js b/packages/entity/index.hooks.js
index 5d6247d..60e0496 100644
--- a/packages/entity/index.hooks.js
+++ b/packages/entity/index.hooks.js
@@ -1,15 +1,29 @@
 export function behaviorContextTypes() {
   return {
-    entity: (entity) => (
-      Object.values(entity.allTraitInstances())
-        .reduce(
-          (r, {constructor: {behaviorContextTypes, describeParams, describeState}}) => ({
-            ...r,
-            ...behaviorContextTypes(),
-            ...describeParams(),
-            ...describeState(),
-          }), {},
-        )
-    ),
+    entity: (entity) => {
+      const traitTypes = !entity
+        ? {}
+        : Object.values(entity.allTraitInstances())
+          .reduce(
+            (r, {constructor: {behaviorContextTypes, describeParams, describeState}}) => ({
+              ...r,
+              ...behaviorContextTypes(),
+              ...describeParams(),
+              ...describeState(),
+            }), {},
+          );
+      return {
+        ...traitTypes,
+        invokeHook: {
+          type: 'object',
+          label: 'Invoke hook.',
+          args: [
+            ['hook', {
+              type: 'string',
+            }],
+          ],
+        },
+      };
+    },
   };
 }
diff --git a/packages/entity/traits/existent.trait.js b/packages/entity/traits/existent.trait.js
index bccb6c3..6dd129e 100644
--- a/packages/entity/traits/existent.trait.js
+++ b/packages/entity/traits/existent.trait.js
@@ -12,8 +12,16 @@ export default class Existent extends decorate(Trait) {
 
   static behaviorContextTypes() {
     return {
+      destroy: {
+        type: 'void',
+        label: 'Destroy',
+      },
+      destroyGently: {
+        type: 'void',
+        label: 'Kill? Then destroy',
+      },
       transition: {
-        type: 'ticking-promise',
+        type: 'void',
         label: 'Transition $1 for $2 seconds using $3.',
         args: [
           ['props', {
diff --git a/packages/entity/traits/perishable.trait.js b/packages/entity/traits/perishable.trait.js
index b2997d1..bebb233 100644
--- a/packages/entity/traits/perishable.trait.js
+++ b/packages/entity/traits/perishable.trait.js
@@ -13,6 +13,15 @@ export default class Perishable extends decorate(Trait) {
     };
   }
 
+  static describeParams() {
+    return {
+      ttl: {
+        type: 'number',
+        label: 'Time-to-live in seconds',
+      },
+    };
+  }
+
   static type() {
     return 'perishable';
   }
diff --git a/packages/entity/traits/positioned.trait.js b/packages/entity/traits/positioned.trait.js
index d2adadb..abb4037 100644
--- a/packages/entity/traits/positioned.trait.js
+++ b/packages/entity/traits/positioned.trait.js
@@ -19,6 +19,10 @@ export default class Positioned extends decorate(Trait) {
 
   static behaviorContextTypes() {
     return {
+      position: {
+        type: 'vector',
+        label: 'Position',
+      },
       setPosition: {
         type: 'void',
         label: 'Set position to $1.',
diff --git a/packages/entity/traits/spawner.trait.js b/packages/entity/traits/spawner.trait.js
index 764262c..e080b63 100644
--- a/packages/entity/traits/spawner.trait.js
+++ b/packages/entity/traits/spawner.trait.js
@@ -15,6 +15,10 @@ export default class Spawner extends decorate(Trait) {
 
   static behaviorContextTypes() {
     return {
+      killAllChildren: {
+        type: 'void',
+        label: 'Kill all spawned children',
+      },
       spawn: {
         type: 'entity',
         label: 'Spawn $1 with $2 extensions.',
@@ -72,6 +76,15 @@ export default class Spawner extends decorate(Trait) {
     };
   }
 
+  static describeParams() {
+    return {
+      spawns: {
+        type: 'object',
+        label: 'Entities that may be spawned',
+      },
+    };
+  }
+
   static defaultState() {
     return {
       isSpawning: true,
@@ -79,6 +92,19 @@ export default class Spawner extends decorate(Trait) {
     };
   }
 
+  static describeState() {
+    return {
+      isSpawning: {
+        type: 'bool',
+        label: 'Is spawning',
+      },
+      maxSpawns: {
+        type: 'number',
+        label: 'Maximum concurrent spawns',
+      },
+    };
+  }
+
   static type() {
     return 'spawner';
   }
diff --git a/packages/graphics/traits/pictured.trait.js b/packages/graphics/traits/pictured.trait.js
index 950f1b8..b2f99b6 100644
--- a/packages/graphics/traits/pictured.trait.js
+++ b/packages/graphics/traits/pictured.trait.js
@@ -25,6 +25,24 @@ export default class Pictured extends decorate(Trait) {
     };
   }
 
+  static describeParams() {
+    return {
+      images: {
+        type: 'object',
+        label: 'Images',
+      },
+    };
+  }
+
+  static describeState() {
+    return {
+      currentImage: {
+        type: 'string',
+        label: 'Current image',
+      },
+    };
+  }
+
   static type() {
     return 'pictured';
   }
diff --git a/packages/graphics/traits/primitive.trait.js b/packages/graphics/traits/primitive.trait.js
index 925681c..233246d 100644
--- a/packages/graphics/traits/primitive.trait.js
+++ b/packages/graphics/traits/primitive.trait.js
@@ -13,6 +13,15 @@ export default class Primitive extends decorate(Trait) {
     };
   }
 
+  static describeParams() {
+    return {
+      primitives: {
+        type: 'object',
+        label: 'Primitives',
+      },
+    };
+  }
+
   static type() {
     return 'primitive';
   }
diff --git a/packages/graphics/traits/textual.trait.js b/packages/graphics/traits/textual.trait.js
index 8022c07..9618cc3 100644
--- a/packages/graphics/traits/textual.trait.js
+++ b/packages/graphics/traits/textual.trait.js
@@ -17,6 +17,19 @@ export default class Textual extends decorate(Trait) {
     };
   }
 
+  static describeState() {
+    return {
+      text: {
+        type: 'string',
+        label: 'Text',
+      },
+      textStyle: {
+        type: 'object',
+        label: 'Text style',
+      },
+    };
+  }
+
   static type() {
     return 'textual';
   }
diff --git a/packages/graphics/traits/visible.trait.js b/packages/graphics/traits/visible.trait.js
index ebd6d0d..e962aca 100644
--- a/packages/graphics/traits/visible.trait.js
+++ b/packages/graphics/traits/visible.trait.js
@@ -57,6 +57,44 @@ export default class Visible extends decorate(Trait) {
     };
   }
 
+  static describeParams() {
+    return {
+      filter: {
+        type: 'object',
+        label: 'Filter',
+      },
+      trackPosition: {
+        type: 'bool',
+        label: 'Track position',
+      },
+    };
+  }
+
+  static describeState() {
+    return {
+      isVisible: {
+        type: 'bool',
+        label: 'Is visible',
+      },
+      opacity: {
+        type: 'number',
+        label: 'Opacity',
+      },
+      rotation: {
+        type: 'number',
+        label: 'Rotation',
+      },
+      visibleScale: {
+        type: 'vector',
+        label: 'Scale',
+      },
+      zIndex: {
+        type: 'number',
+        label: 'Z index',
+      },
+    };
+  }
+
   static type() {
     return 'visible';
   }
diff --git a/packages/physics/traits/collider.trait.js b/packages/physics/traits/collider.trait.js
index 8c6ec16..268d253 100644
--- a/packages/physics/traits/collider.trait.js
+++ b/packages/physics/traits/collider.trait.js
@@ -75,6 +75,35 @@ export default class Collider extends decorate(Trait) {
     }
   }
 
+  static describeParams() {
+    return {
+      activeCollision: {
+        type: 'bool',
+        label: 'Actively check collisions',
+      },
+      collidesWithGroups: {
+        type: 'object',
+        label: 'Collides with groups',
+      },
+      collisionEndActions: {
+        type: 'actions',
+        label: 'Collision ending actions',
+      },
+      collisionStartActions: {
+        type: 'actions',
+        label: 'Collision starting actions',
+      },
+      collisionGroup: {
+        type: 'string',
+        label: 'Collision group',
+      },
+      isSensor: {
+        type: 'bool',
+        label: 'Is sensor',
+      },
+    };
+  }
+
   static describeState() {
     return {
       isCheckingCollisions: {
@@ -83,7 +112,7 @@ export default class Collider extends decorate(Trait) {
       },
       isColliding: {
         type: 'bool',
-        label: 'Is colliding',
+        label: 'Is able to collide',
       },
     }
   }
diff --git a/packages/physics/traits/emitted.trait.js b/packages/physics/traits/emitted.trait.js
index c32c97d..598077c 100644
--- a/packages/physics/traits/emitted.trait.js
+++ b/packages/physics/traits/emitted.trait.js
@@ -8,6 +8,15 @@ const decorate = compose(
 
 export default class Emitted extends decorate(Trait) {
 
+  static behaviorContextTypes() {
+    return {
+      particle: {
+        type: 'particle',
+        label: 'Create particle.',
+      },
+    };
+  }
+
   static defaultParams() {
     return {
       alpha: {
@@ -35,6 +44,51 @@ export default class Emitted extends decorate(Trait) {
     };
   }
 
+  static describeParams() {
+    return {
+      alpha: {
+        type: 'object',
+        label: 'Alpha',
+      },
+      force: {
+        type: 'vector',
+        label: 'Force',
+      },
+      listed: {
+        type: 'bool',
+        label: 'Is listed',
+      },
+      mass: {
+        type: 'number',
+        label: 'Mass',
+      },
+      position: {
+        type: 'vector',
+        label: 'Position',
+      },
+      rotation: {
+        type: 'object',
+        label: 'Rotation',
+      },
+      scale: {
+        type: 'object',
+        label: 'Scale',
+      },
+      transient: {
+        type: 'bool',
+        label: 'Is transient',
+      },
+      ttl: {
+        type: 'number',
+        label: 'Time to live in seconds',
+      },
+      velocity: {
+        type: 'object',
+        label: 'Velocity',
+      },
+    };
+  }
+
   static type() {
     return 'emitted';
   }
diff --git a/packages/physics/traits/emitter.trait.js b/packages/physics/traits/emitter.trait.js
index f4a5dc7..49b17a2 100644
--- a/packages/physics/traits/emitter.trait.js
+++ b/packages/physics/traits/emitter.trait.js
@@ -14,12 +14,56 @@ const decorate = compose(
 
 export default class Emitter extends decorate(Trait) {
 
+  static behaviorContextTypes() {
+    return {
+      emitParticleEntity: {
+        type: 'entity',
+        label: 'Create particle.',
+        args: [
+          ['entity', {
+            type: 'entity',
+          }],
+        ],
+      },
+      emitParticleJson: {
+        type: 'stream',
+        label: 'Create particle.',
+        args: [
+          ['json', {
+            type: 'object',
+          }],
+        ],
+      },
+      emitParticle: {
+        type: 'stream',
+        label: 'Create particle.',
+        args: [
+          ['key', {
+            type: 'string',
+          }],
+          ['json', {
+            type: 'object',
+          }],
+        ],
+      },
+    };
+  }
+
   static defaultParams() {
     return {
       particles: {},
     };
   }
 
+  static describeParams() {
+    return {
+      particles: {
+        type: 'object',
+        label: 'Particles',
+      },
+    };
+  }
+
   static type() {
     return 'emitter';
   }
diff --git a/packages/physics/traits/physical.trait.js b/packages/physics/traits/physical.trait.js
index 9ebc561..764bae7 100644
--- a/packages/physics/traits/physical.trait.js
+++ b/packages/physics/traits/physical.trait.js
@@ -12,6 +12,29 @@ const decorate = compose(
 
 export default class Physical extends decorate(Trait) {
 
+  static behaviorContextTypes() {
+    return {
+      applyForce: {
+        type: 'void',
+        label: 'Apply force.',
+        args: [
+          ['force', {
+            type: 'vector',
+          }],
+        ],
+      },
+      applyImpulse: {
+        type: 'void',
+        label: 'Apply impulse.',
+        args: [
+          ['impulse', {
+            type: 'vector',
+          }],
+        ],
+      },
+    };
+  }
+
   static defaultState() {
     return {
       addedToPhysics: true,
diff --git a/packages/physics/traits/shaped.trait.js b/packages/physics/traits/shaped.trait.js
index 5a86c1a..835bb16 100644
--- a/packages/physics/traits/shaped.trait.js
+++ b/packages/physics/traits/shaped.trait.js
@@ -15,6 +15,15 @@ export default class Shaped extends decorate(Trait) {
     };
   }
 
+  static describeParams() {
+    return {
+      shape: {
+        type: 'object',
+        label: 'Shape',
+      },
+    };
+  }
+
   static type() {
     return 'shaped';
   }
diff --git a/packages/sound/traits/audible.trait.js b/packages/sound/traits/audible.trait.js
index dc558f2..1f2d2ff 100644
--- a/packages/sound/traits/audible.trait.js
+++ b/packages/sound/traits/audible.trait.js
@@ -6,6 +6,15 @@ export default class Audible extends Trait {
 
   static behaviorContextTypes() {
     return {
+      hasSound: {
+        type: 'bool',
+        label: 'Has $1 sound',
+        args: [
+          ['key', {
+            type: 'string',
+          }],
+        ],
+      },
       playSound: {
         type: 'void',
         label: 'Play the $1 sound.',
@@ -24,6 +33,15 @@ export default class Audible extends Trait {
     };
   }
 
+  static describeParams() {
+    return {
+      sounds: {
+        type: 'object',
+        label: 'Sounds',
+      },
+    };
+  }
+
   static type() {
     return 'audible';
   }
diff --git a/packages/timing/traits/animated.trait.js b/packages/timing/traits/animated.trait.js
index e294724..edcfdac 100644
--- a/packages/timing/traits/animated.trait.js
+++ b/packages/timing/traits/animated.trait.js
@@ -30,6 +30,15 @@ export default class Animated extends decorate(Trait) {
     };
   }
 
+  static describeParams() {
+    return {
+      animations: {
+        type: 'object',
+        label: 'Animations',
+      },
+    };
+  }
+
   static describeState() {
     return {
       isAnimating: {
diff --git a/packages/topdown/traits/followed.trait.js b/packages/topdown/traits/followed.trait.js
index 977269f..9529f61 100644
--- a/packages/topdown/traits/followed.trait.js
+++ b/packages/topdown/traits/followed.trait.js
@@ -10,6 +10,15 @@ export default class Followed extends Trait {
     }
   }
 
+  static describeParams() {
+    return {
+      viewSize: {
+        type: 'vector',
+        label: 'View size',
+      },
+    };
+  }
+
   static type() {
     return 'followed';
   }
diff --git a/packages/topdown/traits/layered.trait.js b/packages/topdown/traits/layered.trait.js
index b12931a..517af5c 100644
--- a/packages/topdown/traits/layered.trait.js
+++ b/packages/topdown/traits/layered.trait.js
@@ -3,6 +3,24 @@ import {Vector} from '@avocado/math';
 
 export default class Layered extends Trait {
 
+  static behaviorContextTypes() {
+    return {
+      removeFromLayer: {
+        type: 'void',
+        label: 'Remove from layer.',
+      },
+      setIntoLayer: {
+        type: 'void',
+        label: 'Set into layer $1.',
+        args: [
+          ['layer', {
+            type: 'layer',
+          }],
+        ],
+      },
+    };
+  }
+
   static type() {
     return 'layered';
   }
diff --git a/packages/topdown/traits/roomed.trait.js b/packages/topdown/traits/roomed.trait.js
index 5803883..32d67c5 100644
--- a/packages/topdown/traits/roomed.trait.js
+++ b/packages/topdown/traits/roomed.trait.js
@@ -2,6 +2,24 @@ import {Trait} from '@avocado/entity';
 
 export default class Roomed extends Trait {
 
+  static behaviorContextTypes() {
+    return {
+      detachFromRoom: {
+        type: 'void',
+        label: 'Remove from room.',
+      },
+      attachToRoom: {
+        type: 'void',
+        label: 'Set into room $1.',
+        args: [
+          ['room', {
+            type: 'room',
+          }],
+        ],
+      },
+    };
+  }
+
   static type() {
     return 'roomed';
   }
diff --git a/packages/topdown/traits/tile-entity.trait.js b/packages/topdown/traits/tile-entity.trait.js
index eb7fd34..525d173 100644
--- a/packages/topdown/traits/tile-entity.trait.js
+++ b/packages/topdown/traits/tile-entity.trait.js
@@ -16,6 +16,15 @@ export default class TileEntity extends decorate(Trait) {
     };
   }
 
+  static describeState() {
+    return {
+      tileIndex: {
+        type: 'number',
+        label: 'Tile index',
+      },
+    };
+  }
+
   static type() {
     return 'tile-entity';
   }