Merge pull request #982 from jlowin/title-field-support

src/fastmcp/prompts/prompt.py

@@ -99,6 +99,7 @@ class Prompt(FastMCPComponent, ABC):
             "name": self.name,
             "description": self.description,
             "arguments": arguments,
+            "title": self.title,
         }
         return MCPPrompt(**kwargs | overrides)
 
@@ -106,6 +107,7 @@ class Prompt(FastMCPComponent, ABC):
     def from_function(
         fn: Callable[..., PromptResult | Awaitable[PromptResult]],
         name: str | None = None,
+        title: str | None = None,
         description: str | None = None,
         tags: set[str] | None = None,
         enabled: bool | None = None,
@@ -119,7 +121,12 @@ class Prompt(FastMCPComponent, ABC):
         - A sequence of any of the above
         """
         return FunctionPrompt.from_function(
-            fn=fn, name=name, description=description, tags=tags, enabled=enabled
+            fn=fn,
+            name=name,
+            title=title,
+            description=description,
+            tags=tags,
+            enabled=enabled,
         )
 
     @abstractmethod
@@ -141,6 +148,7 @@ class FunctionPrompt(Prompt):
         cls,
         fn: Callable[..., PromptResult | Awaitable[PromptResult]],
         name: str | None = None,
+        title: str | None = None,
         description: str | None = None,
         tags: set[str] | None = None,
         enabled: bool | None = None,
@@ -232,6 +240,7 @@ class FunctionPrompt(Prompt):
 
         return cls(
             name=func_name,
+            title=title,
             description=description,
             arguments=arguments,
             tags=tags or set(),

src/fastmcp/resources/resource.py

@@ -65,6 +65,7 @@ class Resource(FastMCPComponent, abc.ABC):
         fn: Callable[[], Any],
         uri: str | AnyUrl,
         name: str | None = None,
+        title: str | None = None,
         description: str | None = None,
         mime_type: str | None = None,
         tags: set[str] | None = None,
@@ -74,6 +75,7 @@ class Resource(FastMCPComponent, abc.ABC):
             fn=fn,
             uri=uri,
             name=name,
+            title=title,
             description=description,
             mime_type=mime_type,
             tags=tags,
@@ -111,6 +113,7 @@ class Resource(FastMCPComponent, abc.ABC):
             "name": self.name,
             "description": self.description,
             "mimeType": self.mime_type,
+            "title": self.title,
         }
         return MCPResource(**kwargs | overrides)
 
@@ -149,6 +152,7 @@ class FunctionResource(Resource):
         fn: Callable[[], Any],
         uri: str | AnyUrl,
         name: str | None = None,
+        title: str | None = None,
         description: str | None = None,
         mime_type: str | None = None,
         tags: set[str] | None = None,
@@ -161,6 +165,7 @@ class FunctionResource(Resource):
             fn=fn,
             uri=uri,
             name=name or fn.__name__,
+            title=title,
             description=description or inspect.getdoc(fn),
             mime_type=mime_type or "text/plain",
             tags=tags or set(),

src/fastmcp/resources/template.py

@@ -86,6 +86,7 @@ class ResourceTemplate(FastMCPComponent):
         fn: Callable[..., Any],
         uri_template: str,
         name: str | None = None,
+        title: str | None = None,
         description: str | None = None,
         mime_type: str | None = None,
         tags: set[str] | None = None,
@@ -95,6 +96,7 @@ class ResourceTemplate(FastMCPComponent):
             fn=fn,
             uri_template=uri_template,
             name=name,
+            title=title,
             description=description,
             mime_type=mime_type,
             tags=tags,
@@ -144,6 +146,7 @@ class ResourceTemplate(FastMCPComponent):
             "name": self.name,
             "description": self.description,
             "mimeType": self.mime_type,
+            "title": self.title,
         }
         return MCPResourceTemplate(**kwargs | overrides)
 
@@ -197,6 +200,7 @@ class FunctionResourceTemplate(ResourceTemplate):
         fn: Callable[..., Any],
         uri_template: str,
         name: str | None = None,
+        title: str | None = None,
         description: str | None = None,
         mime_type: str | None = None,
         tags: set[str] | None = None,
@@ -278,6 +282,7 @@ class FunctionResourceTemplate(ResourceTemplate):
         return cls(
             uri_template=uri_template,
             name=func_name,
+            title=title,
             description=description,
             mime_type=mime_type or "text/plain",
             fn=fn,

src/fastmcp/server/server.py

@@ -790,6 +790,7 @@ class FastMCP(Generic[LifespanResultT]):
         name_or_fn: AnyFunction,
         *,
         name: str | None = None,
+        title: str | None = None,
         description: str | None = None,
         tags: set[str] | None = None,
         output_schema: dict[str, Any] | None | NotSetT = NotSet,
@@ -804,6 +805,7 @@ class FastMCP(Generic[LifespanResultT]):
         name_or_fn: str | None = None,
         *,
         name: str | None = None,
+        title: str | None = None,
         description: str | None = None,
         tags: set[str] | None = None,
         output_schema: dict[str, Any] | None | NotSetT = NotSet,
@@ -817,6 +819,7 @@ class FastMCP(Generic[LifespanResultT]):
         name_or_fn: str | AnyFunction | None = None,
         *,
         name: str | None = None,
+        title: str | None = None,
         description: str | None = None,
         tags: set[str] | None = None,
         output_schema: dict[str, Any] | None | NotSetT = NotSet,
@@ -897,6 +900,7 @@ class FastMCP(Generic[LifespanResultT]):
             tool = Tool.from_function(
                 fn,
                 name=tool_name,
+                title=title,
                 description=description,
                 tags=tags,
                 output_schema=output_schema,
@@ -928,6 +932,7 @@ class FastMCP(Generic[LifespanResultT]):
         return partial(
             self.tool,
             name=tool_name,
+            title=title,
             description=description,
             tags=tags,
             output_schema=output_schema,
@@ -1016,6 +1021,7 @@ class FastMCP(Generic[LifespanResultT]):
         uri: str,
         *,
         name: str | None = None,
+        title: str | None = None,
         description: str | None = None,
         mime_type: str | None = None,
         tags: set[str] | None = None,
@@ -1107,6 +1113,7 @@ class FastMCP(Generic[LifespanResultT]):
                     fn=fn,
                     uri_template=uri,
                     name=name,
+                    title=title,
                     description=description,
                     mime_type=mime_type,
                     tags=tags,
@@ -1119,6 +1126,7 @@ class FastMCP(Generic[LifespanResultT]):
                     fn=fn,
                     uri=uri,
                     name=name,
+                    title=title,
                     description=description,
                     mime_type=mime_type,
                     tags=tags,
@@ -1158,6 +1166,7 @@ class FastMCP(Generic[LifespanResultT]):
         name_or_fn: AnyFunction,
         *,
         name: str | None = None,
+        title: str | None = None,
         description: str | None = None,
         tags: set[str] | None = None,
         enabled: bool | None = None,
@@ -1169,6 +1178,7 @@ class FastMCP(Generic[LifespanResultT]):
         name_or_fn: str | None = None,
         *,
         name: str | None = None,
+        title: str | None = None,
         description: str | None = None,
         tags: set[str] | None = None,
         enabled: bool | None = None,
@@ -1179,6 +1189,7 @@ class FastMCP(Generic[LifespanResultT]):
         name_or_fn: str | AnyFunction | None = None,
         *,
         name: str | None = None,
+        title: str | None = None,
         description: str | None = None,
         tags: set[str] | None = None,
         enabled: bool | None = None,
@@ -1275,6 +1286,7 @@ class FastMCP(Generic[LifespanResultT]):
             prompt = Prompt.from_function(
                 fn=fn,
                 name=prompt_name,
+                title=title,
                 description=description,
                 tags=tags,
                 enabled=enabled,
@@ -1303,6 +1315,7 @@ class FastMCP(Generic[LifespanResultT]):
         return partial(
             self.prompt,
             name=prompt_name,
+            title=title,
             description=description,
             tags=tags,
             enabled=enabled,

src/fastmcp/tools/tool.py

@@ -135,12 +135,20 @@ class Tool(FastMCPComponent):
             pass  # No context available
 
     def to_mcp_tool(self, **overrides: Any) -> MCPTool:
+        if self.title:
+            title = self.title
+        elif self.annotations and self.annotations.title:
+            title = self.annotations.title
+        else:
+            title = None
+
         kwargs = {
             "name": self.name,
             "description": self.description,
             "inputSchema": self.parameters,
             "outputSchema": self.output_schema,
             "annotations": self.annotations,
+            "title": title,
         }
         return MCPTool(**kwargs | overrides)
 
@@ -148,6 +156,7 @@ class Tool(FastMCPComponent):
     def from_function(
         fn: Callable[..., Any],
         name: str | None = None,
+        title: str | None = None,
         description: str | None = None,
         tags: set[str] | None = None,
         annotations: ToolAnnotations | None = None,
@@ -160,6 +169,7 @@ class Tool(FastMCPComponent):
         return FunctionTool.from_function(
             fn=fn,
             name=name,
+            title=title,
             description=description,
             tags=tags,
             annotations=annotations,
@@ -219,6 +229,7 @@ class FunctionTool(Tool):
         cls,
         fn: Callable[..., Any],
         name: str | None = None,
+        title: str | None = None,
         description: str | None = None,
         tags: set[str] | None = None,
         annotations: ToolAnnotations | None = None,
@@ -250,6 +261,7 @@ class FunctionTool(Tool):
         return cls(
             fn=parsed_fn.fn,
             name=name or parsed_fn.name,
+            title=title,
             description=description or parsed_fn.description,
             parameters=parsed_fn.input_schema,
             output_schema=output_schema,

src/fastmcp/utilities/components.py

@@ -24,6 +24,10 @@ class FastMCPComponent(FastMCPBaseModel):
     name: str = Field(
         description="The name of the component.",
     )
+    title: str | None = Field(
+        default=None,
+        description="The title of the component for display purposes.",
+    )
     description: str | None = Field(
         default=None,
         description="The description of the component.",
@@ -64,7 +68,7 @@ class FastMCPComponent(FastMCPBaseModel):
         return self.model_dump() == other.model_dump()
 
     def __repr__(self) -> str:
-        return f"{self.__class__.__name__}(name={self.name!r}, description={self.description!r}, tags={self.tags}, enabled={self.enabled})"
+        return f"{self.__class__.__name__}(name={self.name!r}, title={self.title!r}, description={self.description!r}, tags={self.tags}, enabled={self.enabled})"
 
     def enable(self) -> None:
         """Enable the component."""
@@ -73,3 +77,7 @@ class FastMCPComponent(FastMCPBaseModel):
     def disable(self) -> None:
         """Disable the component."""
         self.enabled = False
+
+    def get_display_name(self) -> str:
+        """Get the display name for this component, preferring title over name."""
+        return self.title if self.title is not None else self.name

tests/tools/test_tool.py

@@ -1225,3 +1225,97 @@ class TestAutomaticStructuredContent:
             assert result.data.name == "Bob"
             assert result.data.age == 25
             assert result.data.verified is True
+
+
+class TestToolTitle:
+    """Tests for tool title functionality."""
+
+    def test_tool_with_title(self):
+        """Test that tools can have titles and they appear in MCP conversion."""
+
+        def calculate(x: int, y: int) -> int:
+            """Calculate the sum of two numbers."""
+            return x + y
+
+        tool = Tool.from_function(
+            calculate,
+            name="calc",
+            title="Advanced Calculator Tool",
+            description="Custom description",
+        )
+
+        assert tool.name == "calc"
+        assert tool.title == "Advanced Calculator Tool"
+        assert tool.description == "Custom description"
+
+        # Test MCP conversion includes title
+        mcp_tool = tool.to_mcp_tool()
+        assert mcp_tool.name == "calc"
+        assert (
+            hasattr(mcp_tool, "title") and mcp_tool.title == "Advanced Calculator Tool"
+        )
+
+    def test_tool_without_title(self):
+        """Test that tools without titles use name as display name."""
+
+        def multiply(a: int, b: int) -> int:
+            return a * b
+
+        tool = Tool.from_function(multiply)
+
+        assert tool.name == "multiply"
+        assert tool.title is None
+
+        # Test MCP conversion doesn't include title when None
+        mcp_tool = tool.to_mcp_tool()
+        assert mcp_tool.name == "multiply"
+        assert not hasattr(mcp_tool, "title") or mcp_tool.title is None
+
+    def test_tool_title_priority(self):
+        """Test that explicit title takes priority over annotations.title."""
+        from mcp.types import ToolAnnotations
+
+        def divide(x: int, y: int) -> float:
+            """Divide two numbers."""
+            return x / y
+
+        # Test with both explicit title and annotations.title
+        annotations = ToolAnnotations(title="Annotation Title")
+        tool = Tool.from_function(
+            divide,
+            name="div",
+            title="Explicit Title",
+            annotations=annotations,
+        )
+
+        assert tool.title == "Explicit Title"
+        assert tool.annotations is not None
+        assert tool.annotations.title == "Annotation Title"
+
+        # Explicit title should take priority
+        mcp_tool = tool.to_mcp_tool()
+        assert mcp_tool.title == "Explicit Title"
+
+    def test_tool_annotations_title_fallback(self):
+        """Test that annotations.title is used when no explicit title is provided."""
+        from mcp.types import ToolAnnotations
+
+        def modulo(x: int, y: int) -> int:
+            """Get modulo of two numbers."""
+            return x % y
+
+        # Test with only annotations.title (no explicit title)
+        annotations = ToolAnnotations(title="Annotation Title")
+        tool = Tool.from_function(
+            modulo,
+            name="mod",
+            annotations=annotations,
+        )
+
+        assert tool.title is None
+        assert tool.annotations is not None
+        assert tool.annotations.title == "Annotation Title"
+
+        # Should fall back to annotations.title
+        mcp_tool = tool.to_mcp_tool()
+        assert mcp_tool.title == "Annotation Title"