diff --git a/crates/goose/src/agents/agent.rs b/crates/goose/src/agents/agent.rs
index 397f0d8e0357..e0bd75e51303 100644
--- a/crates/goose/src/agents/agent.rs
+++ b/crates/goose/src/agents/agent.rs
@@ -529,11 +529,11 @@ impl Agent {
                     "tool_execution_failed",
                     &format!("{}: {}", tool_call.name, e),
                 );
-                ToolCallResult::from(Err(ErrorData::new(
-                    ErrorCode::INTERNAL_ERROR,
-                    e.to_string(),
-                    None,
-                )))
+                // Try to downcast to ErrorData to avoid double wrapping
+                let error_data = e.downcast::<ErrorData>().unwrap_or_else(|e| {
+                    ErrorData::new(ErrorCode::INTERNAL_ERROR, e.to_string(), None)
+                });
+                ToolCallResult::from(Err(error_data))
             })
         };
 
diff --git a/crates/goose/src/agents/extension_manager.rs b/crates/goose/src/agents/extension_manager.rs
index bc071ecfa3c0..86192049c2b6 100644
--- a/crates/goose/src/agents/extension_manager.rs
+++ b/crates/goose/src/agents/extension_manager.rs
@@ -1086,7 +1086,11 @@ impl ExtensionManager {
             self.get_client_for_tool(&tool_call.name)
                 .await
                 .ok_or_else(|| {
-                    ErrorData::new(ErrorCode::RESOURCE_NOT_FOUND, tool_call.name.clone(), None)
+                    ErrorData::new(
+                        ErrorCode::RESOURCE_NOT_FOUND,
+                        format!("Tool '{}' not found", tool_call.name),
+                        None,
+                    )
                 })?;
 
         // rsplit returns the iterator in reverse, tool_name is then at 0
@@ -1095,7 +1099,11 @@ impl ExtensionManager {
             .strip_prefix(client_name.as_str())
             .and_then(|s| s.strip_prefix("__"))
             .ok_or_else(|| {
-                ErrorData::new(ErrorCode::RESOURCE_NOT_FOUND, tool_call.name.clone(), None)
+                ErrorData::new(
+                    ErrorCode::RESOURCE_NOT_FOUND,
+                    format!("Invalid tool name format: '{}'", tool_call.name),
+                    None,
+                )
             })?
             .to_string();