[Bug] MLE-STAR Agent crashes with FileNotFoundError when running custom tasks

[Xia-Rahman]

Name of sample affected

python/agents/machine-learning-engineering (MLE-STAR Agent)

Description of issue

The Machine Learning Engineering agent fails to execute custom tasks due to three distinct hardcoding and pathing issues.

1. Hardcoded Default Task: In sub_agents/initialization/agent.py, the prepare_task function is hardcoded to look for "california-housing-prices" and a "task_description.txt" file, regardless of the actual task directory present or selected.
2. Hardcoded File Extension: The code expects .txt descriptions, while the sample data provided in the repo uses .md.
3. Incorrect Relative Paths: In both sub_agents/initialization/agent.py and sub_agents/ensemble/agent.py, the create_workspace function constructs file paths using os.path.join(data_dir, task_name). This results in an incorrect path (e.g., ./machine_learning_engineering/tasks/diabetes) because the agent execution context is already at the project root. It should look for tasks/diabetes.

These issues prevent any custom task from running without manually editing the source code in multiple files.

Environment

• OS & Architecture: Linux (Google Colab / Ubuntu 22.04 x86_64)
• Python version: 3.12
• Java version: N/A (Python sample)
• Other: Poetry (latest)

Reproduction steps or code

1. Clone the adk-samples repository.
2. Navigate to python/agents/machine-learning-engineering.
3. Install dependencies: poetry install.
4. Create a custom task directory tasks/diabetes (or any name) in the project root.
5. Add train.csv, test.csv, and description.md to that folder.
6. Run the agent: adk run machine_learning_engineering.
7. At the prompt [user]:, enter: execute the task.

Error log

Error 1 (Hardcoded task/file extension):

File "/.../sub_agents/initialization/agent.py", line 237, in prepare_task
    task_description = open(
                       ^^^^^
FileNotFoundError: [Errno 2] No such file or directory: './machine_learning_engineering/tasks/california-housing-prices/task_description.txt'

Error 2 (Incorrect relative path after fixing Error 1):

File "/.../sub_agents/initialization/agent.py", line 287, in create_workspace
    files = os.listdir(os.path.join(data_dir, task_name))
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
FileNotFoundError: [Errno 2] No such file or directory: './machine_learning_engineering/tasks/diabetes'

[Roaimkhan]

@happyhuman happy to contribute..

[Xia-Rahman]

@happyhuman happy to contribute..

Thank you