feat: Added the annotations attribute to McpSchema.Tool

Signed-off-by: Sun Yuhan <sunyuhan1998@users.noreply.github.com>

Author: sunyuhan1998

mcp/src/main/java/io/modelcontextprotocol/spec/McpSchema.java

@@ -738,6 +738,17 @@ public record JsonSchema( // @formatter:off
 		@JsonProperty("definitions") Map<String, Object> definitions) {
 	} // @formatter:on
 
+	@JsonInclude(JsonInclude.Include.NON_ABSENT)
+	@JsonIgnoreProperties(ignoreUnknown = true)
+	public record ToolAnnotations( // @formatter:off
+								   @JsonProperty("title")  String title,
+								   @JsonProperty("readOnlyHint")   Boolean readOnlyHint,
+								   @JsonProperty("destructiveHint") Boolean destructiveHint,
+								   @JsonProperty("idempotentHint") Boolean idempotentHint,
+								   @JsonProperty("openWorldHint") Boolean openWorldHint,
+								   @JsonProperty("returnDirect") Boolean returnDirect) {
+	} // @formatter:on
+
 	/**
 	 * Represents a tool that the server provides. Tools enable servers to expose
 	 * executable functionality to the system. Through these tools, you can interact with
@@ -749,17 +760,23 @@ public record JsonSchema( // @formatter:off
 	 * used by clients to improve the LLM's understanding of available tools.
 	 * @param inputSchema A JSON Schema object that describes the expected structure of
 	 * the arguments when calling this tool. This allows clients to validate tool
+	 * @param annotations Additional properties describing a Tool to clients.
 	 * arguments before sending them to the server.
 	 */
 	@JsonInclude(JsonInclude.Include.NON_ABSENT)
 	@JsonIgnoreProperties(ignoreUnknown = true)
 	public record Tool( // @formatter:off
-		@JsonProperty("name") String name,
-		@JsonProperty("description") String description,
-		@JsonProperty("inputSchema") JsonSchema inputSchema) {
+						@JsonProperty("name") String name,
+						@JsonProperty("description") String description,
+						@JsonProperty("inputSchema") JsonSchema inputSchema,
+						@JsonProperty("annotations") ToolAnnotations annotations) {
 
 		public Tool(String name, String description, String schema) {
-			this(name, description, parseSchema(schema));
+			this(name, description, parseSchema(schema), null);
+		}
+
+		public Tool(String name, String description, String schema, ToolAnnotations annotations) {
+			this(name, description, parseSchema(schema), annotations);
 		}
 
 	} // @formatter:on

mcp/src/test/java/io/modelcontextprotocol/spec/McpSchemaTests.java

@@ -606,6 +606,43 @@ void testToolWithComplexSchema() throws Exception {
 		assertThat(deserializedTool.inputSchema().defs()).containsKey("Address");
 	}
 
+	@Test
+	void testToolWithAnnotations() throws Exception {
+		String schemaJson = """
+				{
+					"type": "object",
+					"properties": {
+						"name": {
+							"type": "string"
+						},
+						"value": {
+							"type": "number"
+						}
+					},
+					"required": ["name"]
+				}
+				""";
+		McpSchema.ToolAnnotations annotations = new McpSchema.ToolAnnotations(
+				"A test tool",
+				false,
+				false,
+				false,
+				false,
+				false
+		);
+
+		McpSchema.Tool tool = new McpSchema.Tool("test-tool", "A test tool", schemaJson, annotations);
+
+		String value = mapper.writeValueAsString(tool);
+		assertThatJson(value).when(Option.IGNORING_ARRAY_ORDER)
+				.when(Option.IGNORING_EXTRA_ARRAY_ITEMS)
+				.isObject()
+				.isEqualTo(
+						json("""
+							{"name":"test-tool","description":"A test tool","inputSchema":{"type":"object","properties":{"name":{"type":"string"},"value":{"type":"number"}},"required":["name"]},"annotations":{"title":"A test tool","readOnlyHint":false,"destructiveHint":false,"idempotentHint":false,"openWorldHint":false,"returnDirect":false}}"""));
+	}
+
+
 	@Test
 	void testCallToolRequest() throws Exception {
 		Map<String, Object> arguments = new HashMap<>();