diff --git a/tests/tools/test_schema_sanitizer.py b/tests/tools/test_schema_sanitizer.py
index da6a1e30ad0f..e950049a59b1 100644
--- a/tests/tools/test_schema_sanitizer.py
+++ b/tests/tools/test_schema_sanitizer.py
@@ -867,3 +867,73 @@ def test_unrename_passes_unknown_keys_through():
 def test_sanitize_property_key_empty_falls_back():
     assert sanitize_property_key("~~~") == "___"
     assert sanitize_property_key("") == "param"
+
+
+# ---------------------------------------------------------------------------
+# dependentRequired -- literal property-name strings must survive
+# ---------------------------------------------------------------------------
+
+
+def test_dependent_required_preserved_through_public_api():
+    """dependentRequired values are literal property names, not schemas."""
+    schema = {
+        "type": "object",
+        "properties": {
+            "owner": {"type": "string"},
+            "repo": {"type": "string"},
+            "organization": {"type": "string"},
+        },
+        "dependentRequired": {
+            "owner": ["repo", "organization"],
+            "repo": ["owner"],
+        },
+    }
+    tools = [_tool("t", copy.deepcopy(schema))]
+    out = sanitize_tool_schemas(tools)
+    params = out[0]["function"]["parameters"]
+    dep = params.get("dependentRequired", {})
+    # Values are the original property-name strings unchanged.
+    assert dep.get("owner") == ["repo", "organization"]
+    assert dep.get("repo") == ["owner"]
+    # Normal property schemas are still present and valid.
+    assert params["properties"]["owner"] == {"type": "string"}
+    assert params["properties"]["repo"] == {"type": "string"}
+    assert params["properties"]["organization"] == {"type": "string"}
+
+
+def test_dependent_required_does_not_mutate_original_input():
+    """The original schema's dependentRequired must be unchanged after sanitize."""
+    original_dep = {"owner": ["repo", "organization"], "repo": ["owner"]}
+    schema = {
+        "type": "object",
+        "properties": {
+            "owner": {"type": "string"},
+            "repo": {"type": "string"},
+            "organization": {"type": "string"},
+        },
+        "dependentRequired": {k: list(v) for k, v in original_dep.items()},
+    }
+    saved_copy = copy.deepcopy(schema)
+    tools = [_tool("t", schema)]
+    _ = sanitize_tool_schemas(tools)
+    assert schema == saved_copy
+    assert schema["dependentRequired"] == original_dep
+
+
+def test_dependent_schemas_still_recursively_sanitized():
+    """dependentSchemas (real schemas, not literal lists) must still be sanitized."""
+    schema = {
+        "type": "object",
+        "properties": {
+            "owner": {"type": "string"},
+        },
+        "dependentSchemas": {
+            "owner": {"type": "object"},  # bare object -- needs properties: {}
+        },
+    }
+    tools = [_tool("t", copy.deepcopy(schema))]
+    out = sanitize_tool_schemas(tools)
+    dep_schemas = out[0]["function"]["parameters"]["dependentSchemas"]
+    assert dep_schemas["owner"] == {"type": "object", "properties": {}}, (
+        f"dependentSchemas['owner'] was not fully sanitized: {dep_schemas['owner']!r}"
+    )
diff --git a/tools/schema_sanitizer.py b/tools/schema_sanitizer.py
index 7dbcb1ef87fa..f7b331382bda 100644
--- a/tools/schema_sanitizer.py
+++ b/tools/schema_sanitizer.py
@@ -406,11 +406,13 @@ def _sanitize_node(node: Any, path: str) -> Any:
                 _sanitize_node(item, f"{path}.{key}[{i}]")
                 for i, item in enumerate(value)
             ]
-        elif key in {"required", "enum", "examples"}:
+        elif key in {"required", "enum", "examples", "dependentRequired"}:
             # Schema "sibling" keywords whose values are NOT schemas:
             #  - ``required``: list of property-name strings
             #  - ``enum``: list of literal values (any JSON type)
             #  - ``examples``: list of example values (any JSON type)
+            #  - ``dependentRequired``: mapping of property names to lists of
+            #    required property-name strings (JSON Schema 2020-12)
             # Recursing into these with _sanitize_node() would mis-interpret
             # literal strings like "path" as bare-string schemas and replace
             # them with {"type": "object"} dicts. Pass through unchanged