feat: ToolError migration to ErrorData (#4051)

crates/goose/src/agents/subagent_handler.rs

@@ -1,7 +1,7 @@
 use crate::agents::subagent::SubAgent;
 use crate::agents::subagent_task_config::TaskConfig;
 use anyhow::Result;
-use mcp_core::ToolError;
+use rmcp::model::{ErrorCode, ErrorData};
 
 /// Standalone function to run a complete subagent task
 pub async fn run_complete_subagent_task(
@@ -9,9 +9,13 @@ pub async fn run_complete_subagent_task(
     task_config: TaskConfig,
 ) -> Result<String, anyhow::Error> {
     // Create the subagent with the parent agent's provider
-    let subagent = SubAgent::new(task_config.clone())
-        .await
-        .map_err(|e| ToolError::ExecutionError(format!("Failed to create subagent: {}", e)))?;
+    let subagent = SubAgent::new(task_config.clone()).await.map_err(|e| {
+        ErrorData::new(
+            ErrorCode::INTERNAL_ERROR,
+            format!("Failed to create subagent: {}", e),
+            None,
+        )
+    })?;
 
     // Execute the subagent task
     let messages = subagent