test(anthropic): add advisor tool transformation tests

tests/test_litellm/llms/anthropic/chat/test_anthropic_chat_transformation.py

@@ -12,6 +12,7 @@ from litellm.llms.anthropic.chat.transformation import AnthropicConfig
 from litellm.llms.anthropic.experimental_pass_through.messages.transformation import (
     AnthropicMessagesConfig,
 )
+from litellm.types.llms.anthropic import ANTHROPIC_BETA_HEADER_VALUES
 from litellm.types.utils import ServerToolUse
 
 
@@ -3399,3 +3400,106 @@ def test_extract_response_content_thinking_block_null_thinking():
     assert len(thinking_blocks) == 1
     assert thinking_blocks[0]["thinking"] == "Let me think..."
     assert "Done" in text
+
+
+def test_advisor_tool_map_tool_helper():
+    """advisor_20260301 tool type should not raise ValueError."""
+    config = AnthropicConfig()
+    tool = {
+        "type": "advisor_20260301",
+        "name": "advisor",
+        "model": "claude-opus-4-6",
+    }
+    returned_tool, mcp_server = config._map_tool_helper(tool)  # type: ignore
+    assert returned_tool is not None
+    assert returned_tool["type"] == "advisor_20260301"
+    assert returned_tool["model"] == "claude-opus-4-6"
+    assert mcp_server is None
+
+
+def test_advisor_tool_map_tool_helper_with_optional_fields():
+    """advisor_20260301 tool with max_uses and caching should be mapped correctly."""
+    config = AnthropicConfig()
+    tool = {
+        "type": "advisor_20260301",
+        "name": "advisor",
+        "model": "claude-opus-4-6",
+        "max_uses": 3,
+        "caching": {"type": "ephemeral", "ttl": "5m"},
+    }
+    returned_tool, _ = config._map_tool_helper(tool)  # type: ignore
+    assert returned_tool is not None
+    assert returned_tool["max_uses"] == 3
+    assert returned_tool["caching"] == {"type": "ephemeral", "ttl": "5m"}
+
+
+def test_advisor_tool_map_tool_helper_missing_model():
+    """advisor_20260301 without model should raise ValueError."""
+    config = AnthropicConfig()
+    tool = {"type": "advisor_20260301", "name": "advisor"}
+    with pytest.raises(ValueError, match="valid model"):
+        config._map_tool_helper(tool)  # type: ignore
+
+
+def test_advisor_beta_header_injected():
+    """advisor-tool-2026-03-01 beta header is auto-injected when advisor tool is present."""
+    config = AnthropicConfig()
+    headers: dict = {}
+    optional_params = {
+        "tools": [
+            {
+                "type": "advisor_20260301",
+                "name": "advisor",
+                "model": "claude-opus-4-6",
+            }
+        ]
+    }
+    result = config.update_headers_with_optional_anthropic_beta(headers, optional_params)
+    assert ANTHROPIC_BETA_HEADER_VALUES.ADVISOR_TOOL_2026_03_01.value in result.get(
+        "anthropic-beta", ""
+    )
+
+
+def test_advisor_beta_header_not_injected_without_tool():
+    """advisor-tool-2026-03-01 beta header is NOT added when advisor tool is absent."""
+    config = AnthropicConfig()
+    headers: dict = {}
+    optional_params: dict = {"tools": []}
+    result = config.update_headers_with_optional_anthropic_beta(headers, optional_params)
+    assert "advisor-tool-2026-03-01" not in result.get("anthropic-beta", "")
+
+
+def test_advisor_tool_result_preserved_in_response():
+    """advisor_tool_result blocks are preserved in tool_results (not dropped)."""
+    config = AnthropicConfig()
+    completion_response = {
+        "content": [
+            {"type": "text", "text": "Consulting advisor."},
+            {
+                "type": "server_tool_use",
+                "id": "srvtoolu_abc123",
+                "name": "advisor",
+                "input": {},
+            },
+            {
+                "type": "advisor_tool_result",
+                "tool_use_id": "srvtoolu_abc123",
+                "content": {"type": "advisor_result", "text": "Use a channel-based pattern."},
+            },
+            {"type": "text", "text": "Here is the implementation."},
+        ]
+    }
+    text, _, _, _, tool_calls, _, tool_results, _ = config.extract_response_content(
+        completion_response
+    )
+    assert "Consulting advisor." in text
+    assert "Here is the implementation." in text
+    # server_tool_use (advisor) should be a tool_call
+    assert len(tool_calls) == 1
+    assert tool_calls[0]["function"]["name"] == "advisor"
+    assert tool_calls[0]["id"] == "srvtoolu_abc123"
+    # advisor_tool_result should be in tool_results
+    assert tool_results is not None
+    assert len(tool_results) == 1
+    assert tool_results[0]["type"] == "advisor_tool_result"
+    assert tool_results[0]["tool_use_id"] == "srvtoolu_abc123"