diff --git a/tests/tools/test_clarify_tool.py b/tests/tools/test_clarify_tool.py
new file mode 100644
index 00000000..bcdc4192
--- /dev/null
+++ b/tests/tools/test_clarify_tool.py
@@ -0,0 +1,195 @@
+"""Tests for tools/clarify_tool.py - Interactive clarifying questions."""
+
+import json
+from typing import List, Optional
+
+import pytest
+
+from tools.clarify_tool import (
+    clarify_tool,
+    check_clarify_requirements,
+    MAX_CHOICES,
+    CLARIFY_SCHEMA,
+)
+
+
+class TestClarifyToolBasics:
+    """Basic functionality tests for clarify_tool."""
+
+    def test_simple_question_with_callback(self):
+        """Should return user response for simple question."""
+        def mock_callback(question: str, choices: Optional[List[str]]) -> str:
+            assert question == "What color?"
+            assert choices is None
+            return "blue"
+
+        result = json.loads(clarify_tool("What color?", callback=mock_callback))
+        assert result["question"] == "What color?"
+        assert result["choices_offered"] is None
+        assert result["user_response"] == "blue"
+
+    def test_question_with_choices(self):
+        """Should pass choices to callback and return response."""
+        def mock_callback(question: str, choices: Optional[List[str]]) -> str:
+            assert question == "Pick a number"
+            assert choices == ["1", "2", "3"]
+            return "2"
+
+        result = json.loads(clarify_tool(
+            "Pick a number",
+            choices=["1", "2", "3"],
+            callback=mock_callback
+        ))
+        assert result["question"] == "Pick a number"
+        assert result["choices_offered"] == ["1", "2", "3"]
+        assert result["user_response"] == "2"
+
+    def test_empty_question_returns_error(self):
+        """Should return error for empty question."""
+        result = json.loads(clarify_tool("", callback=lambda q, c: "ignored"))
+        assert "error" in result
+        assert "required" in result["error"].lower()
+
+    def test_whitespace_only_question_returns_error(self):
+        """Should return error for whitespace-only question."""
+        result = json.loads(clarify_tool("   \n\t  ", callback=lambda q, c: "ignored"))
+        assert "error" in result
+
+    def test_no_callback_returns_error(self):
+        """Should return error when no callback is provided."""
+        result = json.loads(clarify_tool("What do you want?"))
+        assert "error" in result
+        assert "not available" in result["error"].lower()
+
+
+class TestClarifyToolChoicesValidation:
+    """Tests for choices parameter validation."""
+
+    def test_choices_trimmed_to_max(self):
+        """Should trim choices to MAX_CHOICES."""
+        choices_passed = []
+
+        def mock_callback(question: str, choices: Optional[List[str]]) -> str:
+            choices_passed.extend(choices or [])
+            return "picked"
+
+        many_choices = ["a", "b", "c", "d", "e", "f", "g"]
+        clarify_tool("Pick one", choices=many_choices, callback=mock_callback)
+
+        assert len(choices_passed) == MAX_CHOICES
+
+    def test_empty_choices_become_none(self):
+        """Empty choices list should become None (open-ended)."""
+        choices_received = ["marker"]
+
+        def mock_callback(question: str, choices: Optional[List[str]]) -> str:
+            choices_received.clear()
+            if choices is not None:
+                choices_received.extend(choices)
+            return "answer"
+
+        clarify_tool("Open question?", choices=[], callback=mock_callback)
+        assert choices_received == []  # Was cleared, nothing added
+
+    def test_choices_with_only_whitespace_stripped(self):
+        """Whitespace-only choices should be stripped out."""
+        choices_received = []
+
+        def mock_callback(question: str, choices: Optional[List[str]]) -> str:
+            choices_received.extend(choices or [])
+            return "answer"
+
+        clarify_tool("Pick", choices=["valid", "  ", "", "also valid"], callback=mock_callback)
+        assert choices_received == ["valid", "also valid"]
+
+    def test_invalid_choices_type_returns_error(self):
+        """Non-list choices should return error."""
+        result = json.loads(clarify_tool(
+            "Question?",
+            choices="not a list",  # type: ignore
+            callback=lambda q, c: "ignored"
+        ))
+        assert "error" in result
+        assert "list" in result["error"].lower()
+
+    def test_choices_converted_to_strings(self):
+        """Non-string choices should be converted to strings."""
+        choices_received = []
+
+        def mock_callback(question: str, choices: Optional[List[str]]) -> str:
+            choices_received.extend(choices or [])
+            return "answer"
+
+        clarify_tool("Pick", choices=[1, 2, 3], callback=mock_callback)  # type: ignore
+        assert choices_received == ["1", "2", "3"]
+
+
+class TestClarifyToolCallbackHandling:
+    """Tests for callback error handling."""
+
+    def test_callback_exception_returns_error(self):
+        """Should return error if callback raises exception."""
+        def failing_callback(question: str, choices: Optional[List[str]]) -> str:
+            raise RuntimeError("User cancelled")
+
+        result = json.loads(clarify_tool("Question?", callback=failing_callback))
+        assert "error" in result
+        assert "Failed to get user input" in result["error"]
+        assert "User cancelled" in result["error"]
+
+    def test_callback_receives_stripped_question(self):
+        """Callback should receive trimmed question."""
+        received_question = []
+
+        def mock_callback(question: str, choices: Optional[List[str]]) -> str:
+            received_question.append(question)
+            return "answer"
+
+        clarify_tool("  Question with spaces  \n", callback=mock_callback)
+        assert received_question[0] == "Question with spaces"
+
+    def test_user_response_stripped(self):
+        """User response should be stripped of whitespace."""
+        def mock_callback(question: str, choices: Optional[List[str]]) -> str:
+            return "  response with spaces  \n"
+
+        result = json.loads(clarify_tool("Q?", callback=mock_callback))
+        assert result["user_response"] == "response with spaces"
+
+
+class TestCheckClarifyRequirements:
+    """Tests for the requirements check function."""
+
+    def test_always_returns_true(self):
+        """clarify tool has no external requirements."""
+        assert check_clarify_requirements() is True
+
+
+class TestClarifySchema:
+    """Tests for the OpenAI function-calling schema."""
+
+    def test_schema_name(self):
+        """Schema should have correct name."""
+        assert CLARIFY_SCHEMA["name"] == "clarify"
+
+    def test_schema_has_description(self):
+        """Schema should have a description."""
+        assert "description" in CLARIFY_SCHEMA
+        assert len(CLARIFY_SCHEMA["description"]) > 50
+
+    def test_schema_question_required(self):
+        """Question parameter should be required."""
+        assert "question" in CLARIFY_SCHEMA["parameters"]["required"]
+
+    def test_schema_choices_optional(self):
+        """Choices parameter should be optional."""
+        assert "choices" not in CLARIFY_SCHEMA["parameters"]["required"]
+
+    def test_schema_choices_max_items(self):
+        """Schema should specify max items for choices."""
+        choices_spec = CLARIFY_SCHEMA["parameters"]["properties"]["choices"]
+        assert choices_spec.get("maxItems") == MAX_CHOICES
+
+    def test_max_choices_is_four(self):
+        """MAX_CHOICES constant should be 4."""
+        assert MAX_CHOICES == 4