diff --git a/app/gui/src/controller/graph/widget.rs b/app/gui/src/controller/graph/widget.rs
index 6765b5dd9d06..8b97e20b230d 100644
--- a/app/gui/src/controller/graph/widget.rs
+++ b/app/gui/src/controller/graph/widget.rs
@@ -392,7 +392,7 @@ impl QueryData {
     /// Generate visualization metadata for this query.
     fn visualization_metadata(&self) -> Metadata {
         let arguments: Vec<Code> = vec![
-            Self::escape_visualization_argument(&self.method_name).into(),
+            format!("(self.{}...)", &self.method_name).into(),
             Self::arg_sequence(&self.arguments).into(),
         ];
 
diff --git a/distribution/lib/Standard/Base/0.0.0-dev/src/Errors/Common.enso b/distribution/lib/Standard/Base/0.0.0-dev/src/Errors/Common.enso
index d004a1f1c7cd..4c2d993c1eb6 100644
--- a/distribution/lib/Standard/Base/0.0.0-dev/src/Errors/Common.enso
+++ b/distribution/lib/Standard/Base/0.0.0-dev/src/Errors/Common.enso
@@ -163,7 +163,7 @@ type No_Such_Method
        Convert the No_Such_Method error to a human-readable format.
     to_display_text : Text
     to_display_text self =
-        target_type_name = if Meta.is_polyglot self.target then self.target.to_display_text else (Meta.type_of self.target).to_display_text
+        target_type_name = if Meta.meta self.target . is_a Meta.Polyglot then self.target.to_display_text else (Meta.type_of self.target).to_display_text
         "Method `"+self.method_name+"` of type "+target_type_name+" could not be found."
 
 @Builtin_Type
diff --git a/distribution/lib/Standard/Base/0.0.0-dev/src/Meta.enso b/distribution/lib/Standard/Base/0.0.0-dev/src/Meta.enso
index 3f224cedc8d5..05455f5f4be6 100644
--- a/distribution/lib/Standard/Base/0.0.0-dev/src/Meta.enso
+++ b/distribution/lib/Standard/Base/0.0.0-dev/src/Meta.enso
@@ -11,6 +11,7 @@ import project.Data.Time.Time_Of_Day.Time_Of_Day
 import project.Data.Time.Time_Zone.Time_Zone
 import project.Data.Vector.Vector
 import project.Nothing.Nothing
+import project.Function.Function as Std_Function
 import project.Polyglot.Java
 
 import project.Error.Error as Base_Error
@@ -217,6 +218,20 @@ type Polyglot
         lang_str = get_polyglot_language self.value
         if lang_str == "java" then Language.Java else Language.Unknown
 
+type Function
+    ## PRIVATE
+    Value value
+
+    ## PRIVATE
+      ADVANCED
+
+      Given a type object, method name and a parameter name, return the associated annotation if it exists.
+
+      Arguments:
+      - parameter_name: The name of the parameter to get the attribute for.
+   get_annotation : Text -> Any
+   get_annotation self parameter_name = Meta.get_annotation self.value... Nothing parameter_name
+
 ## ADVANCED
 
    Checks whether `self` represents the same underlying reference as `value`.
@@ -365,14 +380,16 @@ atom_with_hole factory = @Builtin_Method "Meta.atom_with_hole_builtin"
 
    Arguments:
    - value: The runtime entity to get the meta representation of.
-meta : Any -> Atom | Constructor | Primitive | Polyglot | Unresolved_Symbol | Error
-meta value = if is_atom value then Atom.Value value else
-    if is_atom_constructor value then Constructor.Value value else
-        if is_polyglot value then Polyglot.Value value else
-            if is_unresolved_symbol value then Unresolved_Symbol.Value value else
-                if is_error value then Error.Value value.catch else
-                    if is_type value then Type.Value value.catch else
-                        Primitive.Value value
+meta : Any -> Atom | Constructor | Primitive | Polyglot | Unresolved_Symbol | Error | Function
+meta value =
+    fac_vec = [ Function.Value, Atom.Value, Constructor.Value, Polyglot.Value, Unresolved_Symbol.Value, Error.Value, Type.Value, Primitive.Value ]
+    factories = fac_vec.to_array
+    case meta_builtin -1 value... factories of
+      index : Integer -> meta_builtin index value.catch factories
+      ret -> ret
+
+## PRIVATE
+meta_builtin index value factories = @Builtin_Method "Meta.meta_builtin"
 
 ## PRIVATE
    ADVANCED
@@ -439,59 +456,6 @@ type Language
        An unknown language.
     Unknown
 
-## PRIVATE
-
-   Checks if the provided value is an atom constructor.
-
-   Arguments:
-   - value: The value to check.
-is_atom_constructor : Any -> Boolean
-is_atom_constructor value = @Builtin_Method "Meta.is_atom_constructor"
-
-## PRIVATE
-
-   Checks if the provided value is an atom.
-
-   Arguments:
-   - value: The value to check.
-is_atom : Any -> Boolean
-is_atom value = @Builtin_Method "Meta.is_atom"
-
-## PRIVATE
-
-   Checks if the provided value is a runtime error.
-
-   Arguments:
-   - value: The value to check.
-is_error : Any -> Boolean
-is_error value = @Builtin_Method "Meta.is_error"
-
-## PRIVATE
-
-   Checks if the provided value is a type.
-
-   Arguments:
-   - value: The value to check.
-is_type : Any -> Boolean
-is_type value = @Builtin_Method "Meta.is_type"
-
-## PRIVATE
-
-   Checks if the provided value is a polyglot value.
-
-   Arguments:
-   - value: The value to check.
-is_polyglot : Any -> Boolean
-is_polyglot value = @Builtin_Method "Meta.is_polyglot"
-
-## PRIVATE
-
-   Checks if the provided value is an unresolved symbol.
-
-   Arguments:
-   - value: The value to check.
-is_unresolved_symbol : Any -> Boolean
-is_unresolved_symbol value = @Builtin_Method "Meta.is_unresolved_symbol"
 
 ## PRIVATE
 
diff --git a/distribution/lib/Standard/Visualization/0.0.0-dev/src/Widgets.enso b/distribution/lib/Standard/Visualization/0.0.0-dev/src/Widgets.enso
index 01ce017d3a0a..8a1dd95e7f78 100644
--- a/distribution/lib/Standard/Visualization/0.0.0-dev/src/Widgets.enso
+++ b/distribution/lib/Standard/Visualization/0.0.0-dev/src/Widgets.enso
@@ -6,10 +6,22 @@ from Standard.Base import all
    Returns full annotation data for all requested arguments.
 get_widget_json : Any -> Text -> Vector Text -> Text
 get_widget_json value call_name argument_names =
-    read_annotation argument =
-        annotation = Warning.clear <| Meta.get_annotation value call_name argument
-        case annotation of
-            _ : Function -> annotation value
-            _ -> annotation
-    annotations = argument_names.map (arg -> [arg, read_annotation arg])
+    meta = Meta.meta call_name...
+    annotations = case meta of
+        _ : Meta.Function ->
+            read_new_annotation argument =
+                annotation = Warning.clear <| meta.get_annotation argument
+                case annotation of
+                    _ : Function -> annotation value
+                    _ -> annotation
+            argument_names.map (arg -> [arg, read_new_annotation arg])
+        _ ->
+            read_annotation argument =
+                annotation = Warning.clear <| Meta.get_annotation value call_name argument
+                case annotation of
+                    _ : Function -> annotation value
+                    _ -> annotation
+
+            argument_names.map (arg -> [arg, read_annotation arg])
+
     annotations.to_json
diff --git a/engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/meta/GetAnnotationNode.java b/engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/meta/GetAnnotationNode.java
index bbd28da2867c..d3720942df5b 100644
--- a/engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/meta/GetAnnotationNode.java
+++ b/engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/meta/GetAnnotationNode.java
@@ -1,5 +1,10 @@
 package org.enso.interpreter.node.expression.builtin.meta;
 
+import com.oracle.truffle.api.CompilerDirectives;
+import com.oracle.truffle.api.dsl.Cached;
+import com.oracle.truffle.api.dsl.Specialization;
+import com.oracle.truffle.api.frame.VirtualFrame;
+import com.oracle.truffle.api.library.CachedLibrary;
 import org.enso.interpreter.dsl.BuiltinMethod;
 import org.enso.interpreter.node.BaseNode;
 import org.enso.interpreter.node.callable.thunk.ThunkExecutorNode;
@@ -13,12 +18,6 @@
 import org.enso.interpreter.runtime.scope.ModuleScope;
 import org.enso.interpreter.runtime.state.State;
 
-import com.oracle.truffle.api.CompilerDirectives;
-import com.oracle.truffle.api.dsl.Cached;
-import com.oracle.truffle.api.dsl.Specialization;
-import com.oracle.truffle.api.frame.VirtualFrame;
-import com.oracle.truffle.api.library.CachedLibrary;
-
 @BuiltinMethod(
     type = "Meta",
     name = "get_annotation",
@@ -29,6 +28,27 @@ public abstract class GetAnnotationNode extends BaseNode {
   abstract Object execute(
       VirtualFrame frame, State state, Object target, Object method, Object parameter);
 
+  @Specialization
+  Object doExecute(
+      VirtualFrame frame,
+      State state,
+      Function methodFunction,
+      Object method,
+      Object parameter,
+      @CachedLibrary(limit = "3") TypesLibrary types,
+      @Cached ThunkExecutorNode thunkExecutorNode,
+      @Cached ExpectStringNode expectStringNode
+  ) {
+    String parameterName = expectStringNode.execute(parameter);
+    Annotation annotation = methodFunction.getSchema().getAnnotation(parameterName);
+    if (annotation != null) {
+      Function thunk =
+          Function.thunk(annotation.getExpression().getCallTarget(), frame.materialize());
+      return thunkExecutorNode.executeThunk(frame, thunk, state, getTailStatus());
+    }
+    return EnsoContext.get(this).getNothing();
+  }
+
   @Specialization
   Object doExecute(
       VirtualFrame frame,
diff --git a/engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/meta/IsAtomConstructorNode.java b/engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/meta/IsAtomConstructorNode.java
deleted file mode 100644
index 46abd9e29f0c..000000000000
--- a/engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/meta/IsAtomConstructorNode.java
+++ /dev/null
@@ -1,17 +0,0 @@
-package org.enso.interpreter.node.expression.builtin.meta;
-
-import com.oracle.truffle.api.nodes.Node;
-import org.enso.interpreter.dsl.AcceptsError;
-import org.enso.interpreter.dsl.BuiltinMethod;
-import org.enso.interpreter.runtime.type.TypesGen;
-
-@BuiltinMethod(
-    type = "Meta",
-    name = "is_atom_constructor",
-    description = "Checks if the argument is a constructor.",
-    autoRegister = false)
-public class IsAtomConstructorNode extends Node {
-  boolean execute(@AcceptsError Object value) {
-    return TypesGen.isAtomConstructor(value);
-  }
-}
diff --git a/engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/meta/IsAtomNode.java b/engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/meta/IsAtomNode.java
deleted file mode 100644
index 9d9bf28d214d..000000000000
--- a/engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/meta/IsAtomNode.java
+++ /dev/null
@@ -1,17 +0,0 @@
-package org.enso.interpreter.node.expression.builtin.meta;
-
-import com.oracle.truffle.api.nodes.Node;
-import org.enso.interpreter.dsl.AcceptsError;
-import org.enso.interpreter.dsl.BuiltinMethod;
-import org.enso.interpreter.runtime.callable.atom.Atom;
-
-@BuiltinMethod(
-    type = "Meta",
-    name = "is_atom",
-    description = "Checks if the argument is an atom",
-    autoRegister = false)
-public class IsAtomNode extends Node {
-  boolean execute(@AcceptsError Object value) {
-    return value instanceof Atom;
-  }
-}
diff --git a/engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/meta/IsErrorNode.java b/engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/meta/IsErrorNode.java
deleted file mode 100644
index cdb5f804b5fc..000000000000
--- a/engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/meta/IsErrorNode.java
+++ /dev/null
@@ -1,17 +0,0 @@
-package org.enso.interpreter.node.expression.builtin.meta;
-
-import com.oracle.truffle.api.nodes.Node;
-import org.enso.interpreter.dsl.AcceptsError;
-import org.enso.interpreter.dsl.BuiltinMethod;
-import org.enso.interpreter.runtime.type.TypesGen;
-
-@BuiltinMethod(
-    type = "Meta",
-    name = "is_error",
-    description = "Checks if the argument is an error.",
-    autoRegister = false)
-public class IsErrorNode extends Node {
-  boolean execute(@AcceptsError Object value) {
-    return TypesGen.isDataflowError(value);
-  }
-}
diff --git a/engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/meta/IsPolyglotNode.java b/engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/meta/IsPolyglotNode.java
deleted file mode 100644
index 2abda29de27c..000000000000
--- a/engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/meta/IsPolyglotNode.java
+++ /dev/null
@@ -1,25 +0,0 @@
-package org.enso.interpreter.node.expression.builtin.meta;
-
-import com.oracle.truffle.api.dsl.Specialization;
-import com.oracle.truffle.api.nodes.Node;
-import org.enso.interpreter.dsl.AcceptsError;
-import org.enso.interpreter.dsl.BuiltinMethod;
-import org.enso.interpreter.runtime.EnsoContext;
-
-@BuiltinMethod(
-    type = "Meta",
-    name = "is_polyglot",
-    description = "Checks if the argument is a polyglot value.",
-    autoRegister = false)
-public abstract class IsPolyglotNode extends Node {
-  static IsPolyglotNode build() {
-    return IsPolyglotNodeGen.create();
-  }
-
-  abstract boolean execute(@AcceptsError Object value);
-
-  @Specialization
-  boolean doExecute(Object value) {
-    return EnsoContext.get(this).getEnvironment().isHostObject(value);
-  }
-}
diff --git a/engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/meta/IsTypeNode.java b/engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/meta/IsTypeNode.java
deleted file mode 100644
index 18aa16120c61..000000000000
--- a/engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/meta/IsTypeNode.java
+++ /dev/null
@@ -1,17 +0,0 @@
-package org.enso.interpreter.node.expression.builtin.meta;
-
-import com.oracle.truffle.api.nodes.Node;
-import org.enso.interpreter.dsl.AcceptsError;
-import org.enso.interpreter.dsl.BuiltinMethod;
-import org.enso.interpreter.runtime.data.Type;
-
-@BuiltinMethod(
-    type = "Meta",
-    name = "is_type",
-    description = "Checks if the argument is a type",
-    autoRegister = false)
-public class IsTypeNode extends Node {
-  boolean execute(@AcceptsError Object value) {
-    return value instanceof Type;
-  }
-}
diff --git a/engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/meta/IsUnresolvedSymbolNode.java b/engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/meta/IsUnresolvedSymbolNode.java
deleted file mode 100644
index 69f9d0ada567..000000000000
--- a/engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/meta/IsUnresolvedSymbolNode.java
+++ /dev/null
@@ -1,17 +0,0 @@
-package org.enso.interpreter.node.expression.builtin.meta;
-
-import com.oracle.truffle.api.nodes.Node;
-import org.enso.interpreter.dsl.AcceptsError;
-import org.enso.interpreter.dsl.BuiltinMethod;
-import org.enso.interpreter.runtime.type.TypesGen;
-
-@BuiltinMethod(
-    type = "Meta",
-    name = "is_unresolved_symbol",
-    description = "Checks if the argument is an unresolved symbol.",
-    autoRegister = false)
-public class IsUnresolvedSymbolNode extends Node {
-  boolean execute(@AcceptsError Object value) {
-    return TypesGen.isUnresolvedSymbol(value) || TypesGen.isUnresolvedConversion(value);
-  }
-}
diff --git a/engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/meta/MetaBuiltinNode.java b/engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/meta/MetaBuiltinNode.java
new file mode 100644
index 000000000000..4551777e6a86
--- /dev/null
+++ b/engine/runtime/src/main/java/org/enso/interpreter/node/expression/builtin/meta/MetaBuiltinNode.java
@@ -0,0 +1,55 @@
+package org.enso.interpreter.node.expression.builtin.meta;
+
+import com.oracle.truffle.api.nodes.Node;
+import org.enso.interpreter.dsl.AcceptsError;
+import org.enso.interpreter.dsl.BuiltinMethod;
+import org.enso.interpreter.runtime.EnsoContext;
+import org.enso.interpreter.runtime.callable.atom.Atom;
+import org.enso.interpreter.runtime.callable.atom.AtomConstructor;
+import org.enso.interpreter.runtime.data.Array;
+import org.enso.interpreter.runtime.type.TypesGen;
+
+@BuiltinMethod(
+    type = "Meta",
+    name = "meta_builtin",
+    description = "Find the type and constructs a Meta instances.",
+    autoRegister = false)
+public class MetaBuiltinNode extends Node {
+  Object execute(long index, @AcceptsError Object value, Array factories) {
+    if (index < 0) {
+      index = findIndex(value);
+    }
+    if (index < 0) {
+      return -index;
+    }
+    var factory = (AtomConstructor) factories.getItems()[(int) index];
+    return factory.newInstance(value);
+  }
+
+  private int findIndex(Object value) {
+    if (TypesGen.isFunction(value)) {
+      return 0;
+    }
+    if (value instanceof Atom) {
+      return 1;
+    }
+    if (TypesGen.isAtomConstructor(value)) {
+      return 2;
+    }
+    if (TypesGen.isUnresolvedSymbol(value) || TypesGen.isUnresolvedConversion(value)) {
+      return 4;
+    }
+    if (TypesGen.isDataflowError(value)) {
+      return -5;
+    }
+    if (TypesGen.isType(value)) {
+      return 6;
+    }
+    var ctx = EnsoContext.get(this);
+    if (ctx.getEnvironment().isHostObject(value)) {
+      return 3;
+    }
+    // primitive value
+    return 7;
+  }
+}
diff --git a/engine/runtime/src/main/java/org/enso/interpreter/runtime/scope/ModuleScope.java b/engine/runtime/src/main/java/org/enso/interpreter/runtime/scope/ModuleScope.java
index 72f2d0f1d7b2..f9734bbddeaa 100644
--- a/engine/runtime/src/main/java/org/enso/interpreter/runtime/scope/ModuleScope.java
+++ b/engine/runtime/src/main/java/org/enso/interpreter/runtime/scope/ModuleScope.java
@@ -1,15 +1,7 @@
 package org.enso.interpreter.runtime.scope;
 
-import com.oracle.truffle.api.CompilerDirectives.CompilationFinal;
 import com.oracle.truffle.api.CompilerDirectives.TruffleBoundary;
 import com.oracle.truffle.api.interop.TruffleObject;
-import org.enso.interpreter.runtime.EnsoContext;
-import org.enso.interpreter.runtime.Module;
-import org.enso.interpreter.runtime.callable.function.Function;
-import org.enso.interpreter.runtime.data.Type;
-import org.enso.interpreter.runtime.error.RedefinedMethodException;
-import org.enso.interpreter.runtime.error.RedefinedConversionException;
-
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.HashSet;
@@ -18,6 +10,12 @@
 import java.util.Objects;
 import java.util.Optional;
 import java.util.Set;
+import org.enso.interpreter.runtime.EnsoContext;
+import org.enso.interpreter.runtime.Module;
+import org.enso.interpreter.runtime.callable.function.Function;
+import org.enso.interpreter.runtime.data.Type;
+import org.enso.interpreter.runtime.error.RedefinedConversionException;
+import org.enso.interpreter.runtime.error.RedefinedMethodException;
 
 /** A representation of Enso's per-file top-level scope. */
 public final class ModuleScope implements TruffleObject {
@@ -194,11 +192,14 @@ public Function lookupMethodDefinition(Type type, String name) {
       return definedHere;
     }
 
-    return imports.stream()
-        .map(scope -> scope.getExportedMethod(type, name))
-        .filter(Objects::nonNull)
-        .findFirst()
-        .orElse(null);
+    for (var scope : imports) {
+      var method = scope.getExportedMethod(type, name);
+      if (method != null) {
+        return method;
+      }
+    }
+
+    return null;
   }
 
   @TruffleBoundary
diff --git a/test/Tests/src/Semantic/Meta_Define_Extensions.enso b/test/Tests/src/Semantic/Meta_Define_Extensions.enso
new file mode 100644
index 000000000000..55768b3de113
--- /dev/null
+++ b/test/Tests/src/Semantic/Meta_Define_Extensions.enso
@@ -0,0 +1,7 @@
+import project.Semantic.Meta_Define_Type.Meta_Spec_Type
+
+
+@which (self -> self.b + self.a)
+Meta_Spec_Type.describe_better self which = case which of
+    "mul" -> self.a * self.b
+    _ -> self.a / self.b
diff --git a/test/Tests/src/Semantic/Meta_Define_Type.enso b/test/Tests/src/Semantic/Meta_Define_Type.enso
new file mode 100644
index 000000000000..7e5850fb409d
--- /dev/null
+++ b/test/Tests/src/Semantic/Meta_Define_Type.enso
@@ -0,0 +1,8 @@
+type Meta_Spec_Type
+    Value a b
+
+    @which (self -> self.a+self.b)
+    describe self which="first" = case which of
+        "first" -> self.a
+        _ -> self.b
+
diff --git a/test/Tests/src/Semantic/Meta_Define_Usage.enso b/test/Tests/src/Semantic/Meta_Define_Usage.enso
new file mode 100644
index 000000000000..d4ae2d85acfa
--- /dev/null
+++ b/test/Tests/src/Semantic/Meta_Define_Usage.enso
@@ -0,0 +1,9 @@
+from Standard.Base import Meta, Nothing
+import project.Semantic.Meta_Define_Type.Meta_Spec_Type
+import project.Semantic.Meta_Define_Extensions
+
+call_describe_better it = it.describe_better
+annotate_describe_better it = Meta.get_annotation it "describe_better" "which"
+obtain_describe_better it =
+    fn = it.describe_better...
+    Meta.meta fn
diff --git a/test/Tests/src/Semantic/Meta_Spec.enso b/test/Tests/src/Semantic/Meta_Spec.enso
index 9ce2e1f17fef..9e068ea8ab2f 100644
--- a/test/Tests/src/Semantic/Meta_Spec.enso
+++ b/test/Tests/src/Semantic/Meta_Spec.enso
@@ -16,6 +16,9 @@ from Standard.Test import Test, Test_Suite
 import Standard.Test.Extensions
 import Standard.Test.Test_Result.Test_Result
 
+import project.Semantic.Meta_Define_Type.Meta_Spec_Type
+import project.Semantic.Meta_Define_Usage
+
 type My_Type
     @foo (test_method)
     @baz (My_Type.Value 1 2 3)
@@ -209,7 +212,6 @@ spec =
         Test.specify "constructors of Boolean" <|
             typ = Boolean
 
-            Meta.is_atom typ . should_be_false
             meta_typ = Meta.meta typ
             meta_typ . should_be_a Meta.Type
             meta_typ.name . should_equal "Boolean"
@@ -225,7 +227,6 @@ spec =
         Test.specify "constructors of MyType" <|
             typ = My_Type
 
-            Meta.is_atom typ . should_be_false
             meta_typ = Meta.meta typ
             meta_typ . should_be_a Meta.Type
             meta_typ.name . should_equal "My_Type"
@@ -242,7 +243,6 @@ spec =
         Test.specify "methods of MyType" <|
             typ = My_Type
 
-            Meta.is_atom typ . should_be_false
             meta_typ = Meta.meta typ
             meta_typ . should_be_a Meta.Type
             methods = case meta_typ of
@@ -326,7 +326,7 @@ spec =
             atom = pair.value
             fill = pair.fill
 
-            Meta.is_atom atom . should_be_true
+            Meta.meta atom . is_a Meta.Atom . should_be_true
 
             atom.foo . should_equal 1
             atom.baz . should_equal 3
@@ -366,7 +366,7 @@ spec =
             atom = pair.value
             fill = pair.fill
 
-            Meta.is_atom atom . should_be_true
+            Meta.meta atom . is_a Meta.Atom . should_be_true
 
             case atom.foo of
                 n : Number -> Test.fail "Shouldn't be number yet: "+n
@@ -390,11 +390,40 @@ spec =
             case atom.bar of
                 n : Number -> Test.fail "Not changed to number: "+n
                 _ -> Nothing
-    Test.group "Unresolved symbol"
+
+    Test.group "Unresolved symbol" <|
         Test.specify "should be treated as a Function" <|
             (_.is_nothing) . is_a Function . should_equal True
             (.is_nothing) . is_a Function . should_equal True
             Meta.type_of (_.is_nothing) . should_equal Function
             Meta.type_of (.is_nothing) . should_equal Function
 
+    Test.group "Meta for functions" <|
+        Test.specify "Meta for lambda" <|
+            fn_meta = Meta.meta (x-> 2 * x)
+            case fn_meta of
+                _ : Meta.Function -> Nothing
+                _ -> Test.fail "Expecting Meta.Function: " + (Meta.type_of fn_meta).to_text
+
+    Test.group "Extension methods and get_annotation" <|
+        it = Meta_Spec_Type.Value 6 7
+
+        Test.specify "verify calling everything works" <|
+            it.describe . should_equal 6
+            it.describe "second" . should_equal 7
+            Panic.catch Any (it.describe_better) (_->"Not executed") . should_equal "Not executed"
+            Meta_Define_Usage.call_describe_better it "mul" . should_equal 42
+
+        Test.specify "verify calling everything works" <|
+            wrap = Meta.meta it.describe...
+            describe_anno = wrap.get_annotation "which"
+            describe_anno it . should_equal 13
+
+
+            # Meta_Define_Usage can resolve the describe_better method
+            meta_fn = Meta_Define_Usage.obtain_describe_better it
+            # we can query annotations for the resolved function
+            describe_better_anno = meta_fn.get_annotation "which"
+            describe_better_anno it . should_equal 13
+
 main = Test_Suite.run_main spec