Add McpPromptTrigger and McpPromptArgument annotations

pom.xml

@@ -4,7 +4,7 @@
 	<modelVersion>4.0.0</modelVersion>
 	<groupId>com.microsoft.azure.functions</groupId>
 	<artifactId>azure-functions-java-library</artifactId>
-	<version>3.2.4</version>
+	<version>3.3.0</version>
 	<packaging>jar</packaging>
 	<parent>
 		<groupId>com.microsoft.maven</groupId>

src/main/java/com/microsoft/azure/functions/annotation/McpPromptArgument.java

@@ -0,0 +1,76 @@
+/**
+ * Copyright (c) Microsoft Corporation. All rights reserved.
+ * Licensed under the MIT License. See License.txt in the project root for
+ * license information.
+ */
+
+package com.microsoft.azure.functions.annotation;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Defines a strongly-typed input argument for an MCP prompt function parameter.
+ * <p>
+ * Alternative to using JSON format in {@link McpPromptTrigger#promptArguments()}.
+ * Each annotated parameter receives a specific argument value from the prompt invocation.
+ * Unlike tool properties, prompt arguments are always strings — no type schema is needed.
+ * </p>
+ * <p>
+ * The {@code name()} value serves as both the binding parameter name and the argument name
+ * exposed in the MCP protocol (the Maven plugin patches it into {@code argumentName} in
+ * function.json). This follows the same convention as {@link McpToolProperty} where
+ * {@code name()} is patched into {@code propertyName}.
+ * </p>
+ *
+ * <p>Example:</p>
+ * <pre>
+ * {@literal @}FunctionName("codeReview")
+ * public String codeReview(
+ *     {@literal @}McpPromptTrigger(name = "code_review", description = "Code review prompt") String context,
+ *     {@literal @}McpPromptArgument(
+ *         name = "code",
+ *         description = "The code to review",
+ *         isRequired = true
+ *     ) String code,
+ *     {@literal @}McpPromptArgument(
+ *         name = "language",
+ *         description = "The programming language"
+ *     ) String language
+ * ) {
+ *     return "Please review the following " + language + " code:\n\n" + code;
+ * }
+ * </pre>
+ *
+ * @see McpPromptTrigger
+ * @since 3.3.0
+ */
+@Target({ElementType.PARAMETER})
+@Retention(RetentionPolicy.RUNTIME)
+public @interface McpPromptArgument {
+
+    /**
+     * The argument name used as both the binding parameter name and the MCP protocol
+     * argument identifier. The Maven plugin patches this into {@code argumentName}
+     * in function.json.
+     *
+     * @return The argument name
+     */
+    String name();
+
+    /**
+     * Description of the argument's purpose and usage.
+     *
+     * @return Description of the argument
+     */
+    String description() default "";
+
+    /**
+     * Whether this argument is required for prompt invocation.
+     *
+     * @return true if required, false if optional
+     */
+    boolean isRequired() default false;
+}

src/main/java/com/microsoft/azure/functions/annotation/McpPromptTrigger.java

@@ -0,0 +1,120 @@
+/**
+ * Copyright (c) Microsoft Corporation. All rights reserved.
+ * Licensed under the MIT License. See License.txt in the project root for
+ * license information.
+ */
+
+package com.microsoft.azure.functions.annotation;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Triggers an Azure Function when invoked by the Model Context Protocol (MCP) prompt system.
+ * <p>
+ * This annotation enables Azure Functions to expose prompt templates that MCP-compatible clients
+ * can discover via {@code prompts/list} and invoke via {@code prompts/get} with arguments.
+ * The function returns a plain string (auto-wrapped into a single user message) or a
+ * JSON-serialized {@code GetPromptResult} for multi-message or rich content responses.
+ * </p>
+ *
+ * <p>Example:</p>
+ * <pre>
+ * {@literal @}FunctionName("codeReview")
+ * public String codeReview(
+ *     {@literal @}McpPromptTrigger(
+ *         name = "code_review",
+ *         description = "Generates a code review prompt"
+ *     ) String context,
+ *     {@literal @}McpPromptArgument(
+ *         name = "code",
+ *         description = "The code to review",
+ *         isRequired = true
+ *     ) String code,
+ *     {@literal @}McpPromptArgument(
+ *         name = "language",
+ *         description = "The programming language"
+ *     ) String language
+ * ) {
+ *     return "Please review the following " + language + " code:\n\n" + code;
+ * }
+ * </pre>
+ *
+ * @see McpPromptArgument
+ * @see McpMetadata
+ * @since 3.3.0
+ */
+@Target({ElementType.PARAMETER})
+@Retention(RetentionPolicy.RUNTIME)
+public @interface McpPromptTrigger {
+
+    /**
+     * The variable name used in function.json and also the unique prompt name
+     * that MCP clients use to identify and invoke this prompt.
+     * <p>
+     * This serves as both the binding parameter name and the prompt identifier.
+     * It must be unique across all prompts in the function app.
+     * </p>
+     *
+     * @return The prompt name / parameter binding name
+     */
+    String name();
+
+    /**
+     * Defines how Functions runtime should treat the parameter value. Possible values are:
+     * <ul>
+     * <li>"": get the value as a string, and try to deserialize to actual parameter type like POJO</li>
+     * <li>string: always get the value as a string</li>
+     * <li>binary: get the value as a binary data, and try to deserialize to actual parameter type byte[]</li>
+     * </ul>
+     *
+     * @return The dataType which will be used by the Functions runtime.
+     */
+    String dataType() default "";
+
+    /**
+     * Human-readable description of what this prompt does.
+     *
+     * @return Description of the prompt's purpose
+     */
+    String description() default "";
+
+    /**
+     * Optional human-readable title for display purposes.
+     *
+     * @return The display title, or empty string if not specified
+     */
+    String title() default "";
+
+    /**
+     * JSON array defining expected prompt arguments.
+     * <p>
+     * Each argument should be a JSON object with: name, description, required.
+     * Alternative: use {@link McpPromptArgument} annotations on parameters.
+     * </p>
+     *
+     * <p>Example:</p>
+     * <pre>
+     * [{"name":"code","description":"The code to review","required":true}]
+     * </pre>
+     *
+     * @return JSON array of argument definitions, or empty string
+     */
+    String promptArguments() default "";
+
+    /**
+     * JSON-serialized metadata for the MCP prompt.
+     *
+     * @return JSON metadata string, or empty string if not specified
+     */
+    String metadata() default "";
+
+    /**
+     * JSON array of icons for the MCP prompt.
+     *
+     * @return JSON array of icon definitions, or empty string if not specified
+     */
+    String icons() default "";
+}