diff --git a/evaluator/datasets/polyglot_js/CHANGES.md b/evaluator/datasets/polyglot_js/CHANGES.md
index b83532a0..15519f7f 100644
--- a/evaluator/datasets/polyglot_js/CHANGES.md
+++ b/evaluator/datasets/polyglot_js/CHANGES.md
@@ -336,7 +336,7 @@ Added typing to `promisify()`, `all()`, `allSettled()`, `race()`, and `any()`, a
 
 ## proverb
 
-Added the complete function signature with typing for `proverb()`, including the `...args` rest parameter, as the `main.js` file had no parameters at all.
+Added the complete function signature with typing for `proverb()`, including the `...args` rest parameter, as the `main.js` file had no parameters at all. Explained where the qualifier should be used.
 
 ## pythagorean-triplet
 
@@ -400,7 +400,7 @@ Added the missing `name` property and `reset()` method with type hints. The inst
 
 ## robot-simulator
 
-Added typing to `Robot.bearing`, `Robot.coordinates`, `Robot.place()`, and `Robot.evaluate()`, as it is unclear what the parameter types should be and what the methods should return.
+Added typing to `Robot.bearing`, `Robot.coordinates`, `Robot.place()`, and `Robot.evaluate()`, as it is unclear what the parameter types should be, what errors should be thrown, and what the methods should return.
 
 ## roman-numerals
 
diff --git a/evaluator/datasets/polyglot_js/proverb/main.js b/evaluator/datasets/polyglot_js/proverb/main.js
index fb2aec72..2da2ef1c 100644
--- a/evaluator/datasets/polyglot_js/proverb/main.js
+++ b/evaluator/datasets/polyglot_js/proverb/main.js
@@ -4,7 +4,7 @@
 //
 
 /**
- * @param {...string} args
+ * @param {...string | {qualifier: string}} args - The last argument may be an object with a `qualifier` property. The qualifier should go before the first argument in the conclusion.
  * @return {string}
  */
 export const proverb = (...args) => {
diff --git a/evaluator/datasets/polyglot_js/robot-simulator/main.js b/evaluator/datasets/polyglot_js/robot-simulator/main.js
index 2ccd18f5..873f1df3 100644
--- a/evaluator/datasets/polyglot_js/robot-simulator/main.js
+++ b/evaluator/datasets/polyglot_js/robot-simulator/main.js
@@ -12,21 +12,22 @@ export class InvalidInputError extends Error {
 
 export class Robot {
   /**
-   * @returns {string}
+   * @returns {'north' | 'east' | 'south' | 'west'}
    */
   get bearing() {
     throw new Error('Remove this line and implement the function');
   }
 
   /**
-   * @returns {number[]}
+   * @returns {[number, number]}
    */
   get coordinates() {
     throw new Error('Remove this line and implement the function');
   }
 
   /**
-   * @param {{x: number, y: number, direction: string}} position
+   * @param {{x: number, y: number, direction: 'north' | 'east' | 'south' | 'west'}} position
+   * @throws {InvalidInputError}
    */
   place({ x, y, direction }) {
     throw new Error('Remove this line and implement the function');
diff --git a/evaluator/datasets/polyglot_py/CHANGES.md b/evaluator/datasets/polyglot_py/CHANGES.md
index 8d916cf7..ea4faff5 100644
--- a/evaluator/datasets/polyglot_py/CHANGES.md
+++ b/evaluator/datasets/polyglot_py/CHANGES.md
@@ -159,7 +159,7 @@ Added typing to `recite()`, as it is unclear what the parameter types should be
 
 ## forth
 
-Added typing to `evaluate()`, as it is unclear what the parameter type should be and what the function should return. There are some links that are impossible for the agent to follow. This will be resolved in a future version of our sandbox, where we provide restricted Internet access.
+Added typing to `evaluate()`, as it is unclear what the parameter type should be and what the function should return. Added a missing exception message in the instructions that the tests look for. There are some links that are impossible for the agent to follow. This will be resolved in a future version of our sandbox, where we provide restricted Internet access.
 
 ## gigasecond
 
@@ -395,7 +395,7 @@ Added the missing `name` property and `reset()` method with type hints. The inst
 
 ## robot-simulator
 
-Added typing to `Robot.__init__()`, as it is unclear what the parameter types should be. Added import for `Tuple` type hint.
+Added typing to `Robot.__init__()`, as it is unclear what the parameter types should be. Added import for `Tuple` type hint. Added `Robot.move()`, `Robot.direction`, and `Robot.coordinates` since they are needed by the tests.
 
 ## roman-numerals
 
diff --git a/evaluator/datasets/polyglot_py/forth/instructions.md b/evaluator/datasets/polyglot_py/forth/instructions.md
index b06134fc..b504c1e4 100644
--- a/evaluator/datasets/polyglot_py/forth/instructions.md
+++ b/evaluator/datasets/polyglot_py/forth/instructions.md
@@ -59,4 +59,7 @@ raise ZeroDivisionError("divide by zero")
 
 #an example when the operation is undefined.
 raise ValueError("undefined operation")
+
+# an example when the operation is not allowed.
+raise ValueError('illegal operation')
 ```
diff --git a/evaluator/datasets/polyglot_py/list-ops/main.py b/evaluator/datasets/polyglot_py/list-ops/main.py
index 6021e420..3e244526 100644
--- a/evaluator/datasets/polyglot_py/list-ops/main.py
+++ b/evaluator/datasets/polyglot_py/list-ops/main.py
@@ -21,11 +21,11 @@ def map(function: Callable[[Any], Any], list: list) -> list:
     pass
 
 
-def foldl(function: Callable[[Any, Any], list], list: list, initial: Any) -> Any:  # function(acc, el)
+def foldl(function: Callable[[Any, Any], Any], list: list, initial: Any) -> Any:  # function(acc, el)
     pass
 
 
-def foldr(function: Callable[[Any, Any], list], list: list, initial: Any) -> Any:  # function(acc, el)
+def foldr(function: Callable[[Any, Any], Any], list: list, initial: Any) -> Any:  # function(acc, el)
     pass
 
 
diff --git a/evaluator/datasets/polyglot_py/robot-simulator/main.py b/evaluator/datasets/polyglot_py/robot-simulator/main.py
index 72caa3b5..941622a8 100644
--- a/evaluator/datasets/polyglot_py/robot-simulator/main.py
+++ b/evaluator/datasets/polyglot_py/robot-simulator/main.py
@@ -11,3 +11,14 @@
 class Robot:
     def __init__(self, direction: int = NORTH, x_pos: int = 0, y_pos: int = 0) -> None:
         pass
+
+    def move(self, commands: str) -> None:
+        pass
+
+    @property
+    def direction(self) -> int:
+        pass
+
+    @property
+    def coordinates(self) -> Tuple[int, int]:
+        pass