fix(acp): preserve content audience boundaries (#10493)

crates/goose-test-support/src/mcp.rs

@@ -2,7 +2,7 @@ use crate::session::SESSION_ID_HEADER;
 use crate::ExpectedSessionId;
 use rmcp::model::{
     CallToolResult, ClientNotification, ClientRequest, Content, ErrorCode, Implementation,
-    InitializeResult, Meta, ProtocolVersion, ServerCapabilities, ServerInfo,
+    InitializeResult, Meta, ProtocolVersion, Role, ServerCapabilities, ServerInfo,
 };
 use rmcp::service::{DynService, NotificationContext, RequestContext, ServiceExt, ServiceRole};
 use rmcp::transport::streamable_http_server::{
@@ -108,6 +108,17 @@ impl McpFixtureServer {
             "image/png",
         )]))
     }
+
+    #[tool(
+        description = "Get audience-scoped content",
+        annotations(read_only_hint = true)
+    )]
+    fn get_audience_content(&self) -> Result<CallToolResult, McpError> {
+        Ok(CallToolResult::success(vec![
+            Content::text("visible"),
+            Content::text("provider-only").with_audience(vec![Role::Assistant]),
+        ]))
+    }
 }
 
 #[tool_handler]
@@ -116,7 +127,7 @@ impl ServerHandler for McpFixtureServer {
         InitializeResult::new(ServerCapabilities::builder().enable_tools().build())
             .with_protocol_version(ProtocolVersion::V_2025_03_26)
             .with_server_info(Implementation::new("mcp-fixture", "1.0.0"))
-            .with_instructions("Test server with get_code and get_image tools.")
+            .with_instructions("Test server with code, image, and audience-scoped content tools.")
     }
 }