fix: Improve error messages for invalid tool calls (#6483)

Signed-off-by: J. Carr <jcarr250@protonmail.com>
Co-authored-by: Claude Sonnet 4.5 <noreply@anthropic.com>

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(
+                // Try to downcast to ErrorData to avoid double wrapping
-                    ErrorCode::INTERNAL_ERROR,
+                let error_data = e.downcast::<ErrorData>().unwrap_or_else(|e| {
-                    e.to_string(),
+                    ErrorData::new(ErrorCode::INTERNAL_ERROR, e.to_string(), None)
-                    None,
+                });
-                )))
+                ToolCallResult::from(Err(error_data))
             })
         };
 

crates/goose/src/agents/extension_manager.rs

@@ -1155,14 +1155,22 @@ impl ExtensionManager {
             self.get_client_for_tool(&prefixed_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,
+                    )
                 })?;
 
         let tool_name = prefixed_name
             .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();