Add structured content and MCP prompt sample functions

samples/FunctionsMcpTool/local.settings.json

@@ -2,6 +2,7 @@
   "IsEncrypted": false,
   "Values": {
     "AzureWebJobsStorage": "UseDevelopmentStorage=true",
-    "FUNCTIONS_WORKER_RUNTIME": "java"
+    "FUNCTIONS_WORKER_RUNTIME": "java",
+    "FUNCTIONS_EXTENSIONBUNDLE_SOURCE_URI": "https://cdn-staging.functions.azure.com/public"
   }
 }

samples/FunctionsMcpTool/pom.xml

@@ -12,8 +12,8 @@
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <java.version>17</java.version>
-        <azure.functions.maven.plugin.version>1.40.0</azure.functions.maven.plugin.version>
-        <azure.functions.java.library.version>3.2.2</azure.functions.java.library.version>
+        <azure.functions.maven.plugin.version>1.42.0</azure.functions.maven.plugin.version>
+        <azure.functions.java.library.version>3.3.0</azure.functions.java.library.version>
         <functionAppName>HelloWorld-MCP</functionAppName>
     </properties>
 
@@ -23,6 +23,16 @@
             <artifactId>azure-functions-java-library</artifactId>
             <version>${azure.functions.java.library.version}</version>
         </dependency>
+        <dependency>
+            <groupId>com.microsoft.azure.functions</groupId>
+            <artifactId>azure-functions-java-mcp</artifactId>
+            <version>1.0.0</version>
+        </dependency>
+        <dependency>
+            <groupId>io.modelcontextprotocol.sdk</groupId>
+            <artifactId>mcp-json-jackson2</artifactId>
+            <version>1.1.0</version>
+        </dependency>
         <dependency>
             <groupId>com.google.code.gson</groupId>
             <artifactId>gson</artifactId>

samples/FunctionsMcpTool/src/main/java/com/function/PromptExamples.java

@@ -0,0 +1,88 @@
+package com.function;
+
+import com.microsoft.azure.functions.ExecutionContext;
+import com.microsoft.azure.functions.annotation.FunctionName;
+import com.microsoft.azure.functions.annotation.McpPromptArgument;
+import com.microsoft.azure.functions.annotation.McpPromptTrigger;
+
+/**
+ * Demonstrates MCP Prompt functions that expose prompt templates to MCP clients.
+ * Clients discover prompts via prompts/list and invoke them via prompts/get.
+ * 
+ * Return a plain string (auto-wrapped into a single user message by the host)
+ * or a JSON-serialized GetPromptResult for multi-message / rich content responses.
+ */
+public class PromptExamples {
+
+    /**
+     * A code review prompt with multiple arguments (1 required, 1 optional).
+     * Uses McpPromptArgument annotations to define arguments in a strongly-typed way.
+     */
+    @FunctionName("CodeReviewPrompt")
+    public String codeReviewPrompt(
+            @McpPromptTrigger(
+                    name = "code_review",
+                    description = "Generates a code review prompt for the given code snippet",
+                    title = "Code Review")
+            String context,
+            @McpPromptArgument(
+                    name = "code",
+                    description = "The code to review",
+                    isRequired = true)
+            String code,
+            @McpPromptArgument(
+                    name = "language",
+                    description = "The programming language")
+            String language,
+            final ExecutionContext executionContext) {
+
+        executionContext.getLogger().info("Generating code review prompt");
+
+        String lang = (language != null && !language.isEmpty()) ? language : "unknown";
+        String snippet = (code != null && !code.isEmpty()) ? code : "// no code provided";
+
+        return "Please review the following " + lang + " code and suggest improvements:\n\n```"
+                + lang + "\n" + snippet + "\n```";
+    }
+
+    /**
+     * A summarize prompt with a single required argument and plain string return.
+     * The host auto-wraps the returned string into a PromptMessage with role "user".
+     */
+    @FunctionName("SummarizePrompt")
+    public String summarizePrompt(
+            @McpPromptTrigger(
+                    name = "summarize",
+                    description = "Summarizes the provided text",
+                    title = "Summarize Text")
+            String context,
+            @McpPromptArgument(
+                    name = "text",
+                    description = "The text to summarize",
+                    isRequired = true)
+            String text,
+            final ExecutionContext executionContext) {
+
+        executionContext.getLogger().info("Generating summarize prompt");
+
+        String input = (text != null && !text.isEmpty()) ? text : "No text provided";
+        return "Please provide a concise summary of the following text:\n\n" + input;
+    }
+
+    /**
+     * A prompt with no arguments. Tests the edge case of a prompt
+     * that takes no user input.
+     */
+    @FunctionName("NoArgsPrompt")
+    public String noArgsPrompt(
+            @McpPromptTrigger(
+                    name = "no_args_prompt",
+                    description = "A prompt that requires no arguments",
+                    title = "No Arguments Prompt")
+            String context,
+            final ExecutionContext executionContext) {
+
+        executionContext.getLogger().info("Generating no-args prompt");
+        return "This prompt requires no arguments. Please provide general guidance.";
+    }
+}

samples/FunctionsMcpTool/src/main/java/com/function/StructuredContentExamples.java

@@ -0,0 +1,159 @@
+package com.function;
+
+import com.microsoft.azure.functions.ExecutionContext;
+import com.microsoft.azure.functions.annotation.FunctionName;
+import com.microsoft.azure.functions.annotation.McpToolProperty;
+import com.microsoft.azure.functions.annotation.McpToolTrigger;
+import com.microsoft.azure.functions.mcp.McpContent;
+import com.microsoft.azure.functions.mcp.McpToolResult;
+import io.modelcontextprotocol.spec.McpSchema.Content;
+import io.modelcontextprotocol.spec.McpSchema.ImageContent;
+import io.modelcontextprotocol.spec.McpSchema.TextContent;
+
+import java.util.Arrays;
+import java.util.List;
+
+/**
+ * Demonstrates structured content support in Azure Functions MCP tools.
+ * 
+ * <p>These examples show three approaches for returning rich content from MCP tools:</p>
+ * <ol>
+ *   <li>{@link #getSnippetStructured} — {@code @McpContent}-annotated POJO (automatic text + structured content)</li>
+ *   <li>{@link #renderImage} — Single content block (ImageContentBlock)</li>
+ *   <li>{@link #getMultiContent} — Multiple content blocks (List of ContentBlock)</li>
+ * </ol>
+ * 
+ * <p>Note: These functions require the {@code azure-functions-java-mcp} dependency which provides
+ * the middleware that wraps return values into the MCP result envelope.</p>
+ */
+public class StructuredContentExamples {
+
+    // ========================================================================
+    // Example 1: @McpContent-annotated POJO
+    // The middleware automatically creates both text content (for backwards
+    // compatibility) and structured content (for clients that support it).
+    // ========================================================================
+
+    /**
+     * A snippet POJO decorated with @McpContent. When returned from an MCP tool function,
+     * this will be serialized as both text content (JSON text) and structured content
+     * (JSON object), enabling MCP clients to parse the result programmatically.
+     */
+    @McpContent
+    public static class SnippetResult {
+        private String name;
+        private String content;
+        private String language;
+
+        public SnippetResult() {
+        }
+
+        public SnippetResult(String name, String content, String language) {
+            this.name = name;
+            this.content = content;
+            this.language = language;
+        }
+
+        public String getName() { return name; }
+        public void setName(String name) { this.name = name; }
+        public String getContent() { return content; }
+        public void setContent(String content) { this.content = content; }
+        public String getLanguage() { return language; }
+        public void setLanguage(String language) { this.language = language; }
+    }
+
+    /**
+     * Returns a code snippet as structured content. The {@code @McpContent} annotation
+     * on {@code SnippetResult} tells the middleware to serialize the return value as both
+     * text content and structured content.
+     *
+     * <p>MCP clients that support structured content can parse the JSON object directly.
+     * Older clients will see the JSON as a text string.</p>
+     */
+    @FunctionName("GetSnippetStructured")
+    public SnippetResult getSnippetStructured(
+            @McpToolTrigger(
+                    name = "getSnippetStructured",
+                    description = "Gets a code snippet with structured content support.")
+            String context,
+            @McpToolProperty(
+                    name = "snippetName",
+                    propertyType = "string",
+                    description = "The name of the snippet to retrieve.",
+                    isRequired = true)
+            String snippetName,
+            final ExecutionContext executionContext) {
+
+        executionContext.getLogger().info("Getting structured snippet: " + snippetName);
+
+        return new SnippetResult(
+                snippetName,
+                "public class HelloWorld { public static void main(String[] args) { System.out.println(\"Hello!\"); } }",
+                "java"
+        );
+    }
+
+    // ========================================================================
+    // Example 2: Single content block (ImageContentBlock)
+    // For returning rich content types like images.
+    // ========================================================================
+
+    /**
+     * Returns an image as a single content block. The middleware wraps this
+     * in an MCP result envelope automatically.
+     */
+    @FunctionName("RenderImage")
+    public ImageContent renderImage(
+            @McpToolTrigger(
+                    name = "renderImage",
+                    description = "Returns a base64-encoded image.")
+            String context,
+            @McpToolProperty(
+                    name = "data",
+                    propertyType = "string",
+                    description = "Base64-encoded image data.",
+                    isRequired = true)
+            String data,
+            @McpToolProperty(
+                    name = "mimeType",
+                    propertyType = "string",
+                    description = "MIME type of the image (e.g., image/png).")
+            String mimeType,
+            final ExecutionContext executionContext) {
+
+        executionContext.getLogger().info("Rendering image with MIME type: " + mimeType);
+
+        return new ImageContent(null, data, mimeType != null ? mimeType : "image/png");
+    }
+
+    // ========================================================================
+    // Example 3: Multiple content blocks
+    // For returning a list of mixed content types in a single response.
+    // ========================================================================
+
+    /**
+     * Returns multiple content blocks — a text description followed by an image.
+     * The middleware wraps this as a multi-content result.
+     */
+    @FunctionName("GetMultiContent")
+    public List<Content> getMultiContent(
+            @McpToolTrigger(
+                    name = "getMultiContent",
+                    description = "Returns multiple content blocks including text and an image.")
+            String context,
+            @McpToolProperty(
+                    name = "imageData",
+                    propertyType = "string",
+                    description = "Base64-encoded image data.",
+                    isRequired = true)
+            String imageData,
+            final ExecutionContext executionContext) {
+
+        executionContext.getLogger().info("Generating multi-content response");
+
+        return Arrays.asList(
+                new TextContent("Here is the requested image:"),
+                new ImageContent(null, imageData, "image/png")
+        );
+    }
+}

samples/McpWeatherApp/pom.xml

@@ -13,7 +13,7 @@
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <java.version>17</java.version>
         <azure.functions.maven.plugin.version>1.41.0</azure.functions.maven.plugin.version>
-        <azure.functions.java.library.version>3.2.4</azure.functions.java.library.version>
+        <azure.functions.java.library.version>3.3.0</azure.functions.java.library.version>
         <functionAppName>McpWeatherApp</functionAppName>
     </properties>