diff --git a/src/strands/models/anthropic.py b/src/strands/models/anthropic.py
index b5f6fcf91..9d57049ba 100644
--- a/src/strands/models/anthropic.py
+++ b/src/strands/models/anthropic.py
@@ -232,6 +232,7 @@ def format_request(
                     "name": tool_spec["name"],
                     "description": tool_spec["description"],
                     "input_schema": tool_spec["inputSchema"]["json"],
+                    **({"strict": tool_spec["strict"]} if "strict" in tool_spec else {}),
                 }
                 for tool_spec in tool_specs or []
             ],
diff --git a/src/strands/models/bedrock.py b/src/strands/models/bedrock.py
index bab4031ed..9a886c14d 100644
--- a/src/strands/models/bedrock.py
+++ b/src/strands/models/bedrock.py
@@ -255,6 +255,7 @@ def _format_request(
                                         "name": tool_spec["name"],
                                         "description": tool_spec["description"],
                                         "inputSchema": tool_spec["inputSchema"],
+                                        **({"strict": tool_spec["strict"]} if "strict" in tool_spec else {}),
                                     }
                                 }
                                 for tool_spec in tool_specs
diff --git a/src/strands/models/openai.py b/src/strands/models/openai.py
index 2b217ad91..a2a40a8a6 100644
--- a/src/strands/models/openai.py
+++ b/src/strands/models/openai.py
@@ -461,6 +461,7 @@ def format_request(
                         "name": tool_spec["name"],
                         "description": tool_spec["description"],
                         "parameters": tool_spec["inputSchema"]["json"],
+                        **({"strict": tool_spec["strict"]} if "strict" in tool_spec else {}),
                     },
                 }
                 for tool_spec in tool_specs or []
diff --git a/src/strands/models/openai_responses.py b/src/strands/models/openai_responses.py
index 0ace9645f..570a0e0e3 100644
--- a/src/strands/models/openai_responses.py
+++ b/src/strands/models/openai_responses.py
@@ -418,6 +418,7 @@ def _format_request(
                     "name": tool_spec["name"],
                     "description": tool_spec.get("description", ""),
                     "parameters": tool_spec["inputSchema"]["json"],
+                    **({"strict": tool_spec["strict"]} if "strict" in tool_spec else {}),
                 }
                 for tool_spec in tool_specs
             ]
@@ -502,9 +503,7 @@ def _format_request_messages(cls, messages: Messages) -> list[dict[str, Any]]:
         ]
 
     @classmethod
-    def _format_request_message_content(
-        cls, content: ContentBlock, *, role: Role = "user"
-    ) -> dict[str, Any]:
+    def _format_request_message_content(cls, content: ContentBlock, *, role: Role = "user") -> dict[str, Any]:
         """Format an OpenAI compatible content block.
 
         Args:
diff --git a/src/strands/tools/decorator.py b/src/strands/tools/decorator.py
index 9207df9b8..2a778bc31 100644
--- a/src/strands/tools/decorator.py
+++ b/src/strands/tools/decorator.py
@@ -725,6 +725,7 @@ def tool(
     inputSchema: JSONSchema | None = None,
     name: str | None = None,
     context: bool | str = False,
+    strict: bool | None = None,
 ) -> Callable[[Callable[P, R]], DecoratedFunctionTool[P, R]]: ...
 # Suppressing the type error because we want callers to be able to use both `tool` and `tool()` at the
 # call site, but the actual implementation handles that and it's not representable via the type-system
@@ -734,6 +735,7 @@ def tool(  # type: ignore
     inputSchema: JSONSchema | None = None,
     name: str | None = None,
     context: bool | str = False,
+    strict: bool | None = None,
 ) -> DecoratedFunctionTool[P, R] | Callable[[Callable[P, R]], DecoratedFunctionTool[P, R]]:
     """Decorator that transforms a Python function into a Strands tool.
 
@@ -762,6 +764,8 @@ def tool(  # type: ignore
         context: When provided, places an object in the designated parameter. If True, the param name
             defaults to 'tool_context', or if an override is needed, set context equal to a string to designate
             the param name.
+        strict: Optional Boolean that ensures the model will only output tool calls containing parameters
+            that perfectly match the defined input schema.
 
     Returns:
         An AgentTool that also mimics the original function when invoked
@@ -816,6 +820,8 @@ def decorator(f: T) -> "DecoratedFunctionTool[P, R]":
             tool_spec["description"] = description
         if inputSchema is not None:
             tool_spec["inputSchema"] = inputSchema
+        if strict is not None:
+            tool_spec["strict"] = strict
 
         tool_name = tool_spec.get("name", f.__name__)
 
diff --git a/src/strands/types/tools.py b/src/strands/types/tools.py
index 088c83bdb..8c7e5109f 100644
--- a/src/strands/types/tools.py
+++ b/src/strands/types/tools.py
@@ -30,12 +30,17 @@ class ToolSpec(TypedDict):
         outputSchema: Optional JSON Schema defining the expected output format.
             Note: Not all model providers support this field. Providers that don't
             support it should filter it out before sending to their API.
+        strict: Optional Boolean that ensures the model will only output tool calls
+            containing parameters that perfectly match the defined input schema.
+            Note: Not all model providers support this field. Providers that don't
+            support it should filter it out before sending to their API.
     """
 
     description: str
     inputSchema: JSONSchema
     name: str
     outputSchema: NotRequired[JSONSchema]
+    strict: NotRequired[bool]
 
 
 class Tool(TypedDict):
diff --git a/tests/strands/models/test_anthropic.py b/tests/strands/models/test_anthropic.py
index c5aff8062..b80cd9d56 100644
--- a/tests/strands/models/test_anthropic.py
+++ b/tests/strands/models/test_anthropic.py
@@ -440,6 +440,31 @@ def test_format_request_tool_choice_auto(model, messages, model_id, max_tokens):
     assert tru_request == exp_request
 
 
+def test_format_request_tool_specs_with_strict(model, messages, model_id, max_tokens):
+    tool_specs = [
+        {"description": "test tool", "name": "test_tool", "inputSchema": {"json": {"key": "value"}}, "strict": True}
+    ]
+    tru_request = model.format_request(messages, tool_specs)
+
+    assert tru_request["tools"][0]["strict"] is True
+
+
+def test_format_request_tool_specs_with_strict_false(model, messages, model_id, max_tokens):
+    tool_specs = [
+        {"description": "test tool", "name": "test_tool", "inputSchema": {"json": {"key": "value"}}, "strict": False}
+    ]
+    tru_request = model.format_request(messages, tool_specs)
+
+    assert tru_request["tools"][0]["strict"] is False
+
+
+def test_format_request_tool_specs_without_strict(model, messages, model_id, max_tokens):
+    tool_specs = [{"description": "test tool", "name": "test_tool", "inputSchema": {"json": {"key": "value"}}}]
+    tru_request = model.format_request(messages, tool_specs)
+
+    assert "strict" not in tru_request["tools"][0]
+
+
 def test_format_request_tool_choice_any(model, messages, model_id, max_tokens):
     tool_specs = [{"description": "test tool", "name": "test_tool", "inputSchema": {"json": {"key": "value"}}}]
     tool_choice = {"any": {}}
diff --git a/tests/strands/models/test_bedrock.py b/tests/strands/models/test_bedrock.py
index 89c4df70d..e074d9860 100644
--- a/tests/strands/models/test_bedrock.py
+++ b/tests/strands/models/test_bedrock.py
@@ -471,6 +471,44 @@ def test_format_request_tool_specs(model, messages, model_id, tool_spec):
     assert tru_request == exp_request
 
 
+def test_format_request_tool_specs_with_strict(model, messages, model_id):
+    strict_tool_spec = {
+        "description": "description",
+        "name": "name",
+        "inputSchema": {"key": "val"},
+        "strict": True,
+    }
+    tru_request = model._format_request(messages, tool_specs=[strict_tool_spec])
+    tool_in_request = tru_request["toolConfig"]["tools"][0]["toolSpec"]
+
+    assert tool_in_request["strict"] is True
+
+
+def test_format_request_tool_specs_with_strict_false(model, messages, model_id):
+    strict_false_tool_spec = {
+        "description": "description",
+        "name": "name",
+        "inputSchema": {"key": "val"},
+        "strict": False,
+    }
+    tru_request = model._format_request(messages, tool_specs=[strict_false_tool_spec])
+    tool_in_request = tru_request["toolConfig"]["tools"][0]["toolSpec"]
+
+    assert tool_in_request["strict"] is False
+
+
+def test_format_request_tool_specs_without_strict(model, messages, model_id):
+    tool_spec_no_strict = {
+        "description": "description",
+        "name": "name",
+        "inputSchema": {"key": "val"},
+    }
+    tru_request = model._format_request(messages, tool_specs=[tool_spec_no_strict])
+    tool_in_request = tru_request["toolConfig"]["tools"][0]["toolSpec"]
+
+    assert "strict" not in tool_in_request
+
+
 def test_format_request_tool_choice_auto(model, messages, model_id, tool_spec):
     tool_choice = {"auto": {}}
     tru_request = model._format_request(messages, [tool_spec], tool_choice=tool_choice)
diff --git a/tests/strands/models/test_openai.py b/tests/strands/models/test_openai.py
index 241c22b64..f806223f4 100644
--- a/tests/strands/models/test_openai.py
+++ b/tests/strands/models/test_openai.py
@@ -503,6 +503,44 @@ def test_format_request(model, messages, tool_specs, system_prompt):
     assert tru_request == exp_request
 
 
+def test_format_request_tool_specs_with_strict(model, messages, system_prompt):
+    strict_tool_specs = [
+        {
+            "name": "test_tool",
+            "description": "A test tool",
+            "inputSchema": {
+                "json": {"type": "object", "properties": {"input": {"type": "string"}}, "required": ["input"]}
+            },
+            "strict": True,
+        }
+    ]
+    tru_request = model.format_request(messages, strict_tool_specs, system_prompt)
+
+    assert tru_request["tools"][0]["function"]["strict"] is True
+
+
+def test_format_request_tool_specs_with_strict_false(model, messages, system_prompt):
+    strict_false_tool_specs = [
+        {
+            "name": "test_tool",
+            "description": "A test tool",
+            "inputSchema": {
+                "json": {"type": "object", "properties": {"input": {"type": "string"}}, "required": ["input"]}
+            },
+            "strict": False,
+        }
+    ]
+    tru_request = model.format_request(messages, strict_false_tool_specs, system_prompt)
+
+    assert tru_request["tools"][0]["function"]["strict"] is False
+
+
+def test_format_request_tool_specs_without_strict(model, messages, tool_specs, system_prompt):
+    tru_request = model.format_request(messages, tool_specs, system_prompt)
+
+    assert "strict" not in tru_request["tools"][0]["function"]
+
+
 def test_format_request_with_tool_choice_auto(model, messages, tool_specs, system_prompt):
     tool_choice = {"auto": {}}
     tru_request = model.format_request(messages, tool_specs, system_prompt, tool_choice)
diff --git a/tests/strands/models/test_openai_responses.py b/tests/strands/models/test_openai_responses.py
index 9c84f4ed4..1c1607345 100644
--- a/tests/strands/models/test_openai_responses.py
+++ b/tests/strands/models/test_openai_responses.py
@@ -348,6 +348,53 @@ def test_format_request(model, messages, tool_specs, system_prompt):
     assert tru_request == exp_request
 
 
+def test_format_request_tool_specs_with_strict(model, messages, system_prompt):
+    strict_tool_specs = [
+        {
+            "name": "test_tool",
+            "description": "A test tool",
+            "inputSchema": {
+                "json": {"type": "object", "properties": {"input": {"type": "string"}}, "required": ["input"]}
+            },
+            "strict": True,
+        }
+    ]
+    tru_request = model._format_request(messages, strict_tool_specs, system_prompt)
+
+    assert tru_request["tools"][0]["strict"] is True
+
+
+def test_format_request_tool_specs_with_strict_false(model, messages, system_prompt):
+    strict_false_tool_specs = [
+        {
+            "name": "test_tool",
+            "description": "A test tool",
+            "inputSchema": {
+                "json": {"type": "object", "properties": {"input": {"type": "string"}}, "required": ["input"]}
+            },
+            "strict": False,
+        }
+    ]
+    tru_request = model._format_request(messages, strict_false_tool_specs, system_prompt)
+
+    assert tru_request["tools"][0]["strict"] is False
+
+
+def test_format_request_tool_specs_without_strict(model, messages, system_prompt):
+    tool_specs = [
+        {
+            "name": "test_tool",
+            "description": "A test tool",
+            "inputSchema": {
+                "json": {"type": "object", "properties": {"input": {"type": "string"}}, "required": ["input"]}
+            },
+        }
+    ]
+    tru_request = model._format_request(messages, tool_specs, system_prompt)
+
+    assert "strict" not in tru_request["tools"][0]
+
+
 @pytest.mark.parametrize(
     ("event", "exp_chunk"),
     [
diff --git a/tests/strands/tools/test_decorator.py b/tests/strands/tools/test_decorator.py
index cc1158983..579bc0a5b 100644
--- a/tests/strands/tools/test_decorator.py
+++ b/tests/strands/tools/test_decorator.py
@@ -90,6 +90,33 @@ def test_tool_spec(identity_tool):
     assert tru_spec == exp_spec
 
 
+def test_tool_spec_with_strict_true():
+    @strands.tool(strict=True)
+    def my_tool(param: str) -> str:
+        """A tool."""
+        return param
+
+    assert my_tool.tool_spec["strict"] is True
+
+
+def test_tool_spec_with_strict_false():
+    @strands.tool(strict=False)
+    def my_tool(param: str) -> str:
+        """A tool."""
+        return param
+
+    assert my_tool.tool_spec["strict"] is False
+
+
+def test_tool_spec_without_strict():
+    @strands.tool
+    def my_tool(param: str) -> str:
+        """A tool."""
+        return param
+
+    assert "strict" not in my_tool.tool_spec
+
+
 @pytest.mark.parametrize("identity_tool", ["identity_invoke", "identity_invoke_async"], indirect=True)
 def test_tool_type(identity_tool):
     tru_type = identity_tool.tool_type