apply refactoring

Author: ihrpr

src/mcp/server/fastmcp/server.py

@@ -958,10 +958,13 @@ async def get_prompt(self, name: str, arguments: dict[str, Any] | None = None) -
         """Get a prompt by name with arguments."""
         try:
             prompt = self._prompt_manager.get_prompt(name)
-            messages = await self._prompt_manager.render_prompt(name, arguments)
-
+            if not prompt:
+                raise ValueError(f"Unknown prompt: {name}")
+            
+            messages = await prompt.render(arguments)
+            
             return GetPromptResult(
-                description=getattr(prompt, "description", None),
+                description=prompt.description,
                 messages=pydantic_core.to_jsonable_python(messages),
             )
         except Exception as e:

tests/server/fastmcp/test_server.py

@@ -995,6 +995,33 @@ def fn(name: str) -> str:
             result = await client.get_prompt("fn", {"name": "World"})
             assert result.description == "Test prompt description"
 
+    @pytest.mark.anyio
+    async def test_get_prompt_without_description(self):
+        """Test getting a prompt without description returns None."""
+        mcp = FastMCP()
+
+        @mcp.prompt()  # No description provided
+        def fn(name: str) -> str:
+            return f"Hello, {name}!"
+
+        async with client_session(mcp._mcp_server) as client:
+            result = await client.get_prompt("fn", {"name": "World"})
+            assert result.description is None
+
+    @pytest.mark.anyio
+    async def test_get_prompt_with_docstring_description(self):
+        """Test prompt uses docstring as description when not explicitly provided."""
+        mcp = FastMCP()
+
+        @mcp.prompt()
+        def fn(name: str) -> str:
+            """This is the function docstring."""
+            return f"Hello, {name}!"
+
+        async with client_session(mcp._mcp_server) as client:
+            result = await client.get_prompt("fn", {"name": "World"})
+            assert result.description == "This is the function docstring."
+
     @pytest.mark.anyio
     async def test_get_prompt_with_resource(self):
         """Test getting a prompt that returns resource content."""