fix: update McpToolCallResponse type for SDK v1.26.0 compatibility

- Add resource_link content type variant to McpToolCallResponse union
- Add optional annotations, _meta fields on all content item types
- Add optional structuredContent field at top level
- Handle resource_link content in UseMcpToolTool.processToolContent()

Resolves TS2322 error where SDK CallToolResultSchema (with new
resource_link type) was not assignable to McpToolCallResponse.

packages/types/src/mcp.ts

@@ -99,22 +99,48 @@ export type McpResourceResponse = {
 	}>
 }
 
+/**
+ * Annotations that can be attached to content items in MCP tool call responses.
+ * Used to indicate audience targeting, priority, and modification timestamps.
+ */
+export type McpContentAnnotations = {
+	audience?: Array<"user" | "assistant">
+	priority?: number
+	lastModified?: string
+}
+
 export type McpToolCallResponse = {
 	_meta?: Record<string, any> // eslint-disable-line @typescript-eslint/no-explicit-any
 	content: Array<
 		| {
 				type: "text"
 				text: string
+				annotations?: McpContentAnnotations
+				_meta?: Record<string, unknown>
 		  }
 		| {
 				type: "image"
 				data: string
 				mimeType: string
+				annotations?: McpContentAnnotations
+				_meta?: Record<string, unknown>
 		  }
 		| {
 				type: "audio"
 				data: string
 				mimeType: string
+				annotations?: McpContentAnnotations
+				_meta?: Record<string, unknown>
+		  }
+		| {
+				type: "resource_link"
+				uri: string
+				name: string
+				description?: string
+				mimeType?: string
+				title?: string
+				annotations?: McpContentAnnotations
+				_meta?: Record<string, unknown>
 		  }
 		| {
 				type: "resource"
@@ -123,9 +149,13 @@ export type McpToolCallResponse = {
 					mimeType?: string
 					text?: string
 					blob?: string
+					_meta?: Record<string, unknown>
 				}
+				annotations?: McpContentAnnotations
+				_meta?: Record<string, unknown>
 		  }
 	>
+	structuredContent?: Record<string, unknown>
 	isError?: boolean
 }
 

src/core/tools/UseMcpToolTool.ts

@@ -271,6 +271,13 @@ export class UseMcpToolTool extends BaseTool<"use_mcp_tool"> {
 					const { blob: _, ...rest } = item.resource
 					return JSON.stringify(rest, null, 2)
 				}
+				if (item.type === "resource_link") {
+					const { uri, name, description, mimeType } = item
+					const parts: Record<string, string> = { uri, name }
+					if (description) parts.description = description
+					if (mimeType) parts.mimeType = mimeType
+					return JSON.stringify(parts, null, 2)
+				}
 				if (item.type === "image") {
 					// Handle image content (MCP image content has mimeType and data properties)
 					if (item.mimeType && item.data) {