mod-003d-missing-required-method-docstring-sections

A documentation rule for method docstrings, which are written notes explaining how a method works and what it accepts or returns. Each method must include Parameters and Returns sections in the project's required format.

In plain words
What is it for?
Use it when adding or changing methods, including their inputs, returned values, and any allowed supporting sections.
Why use it?
It gives readers and documentation tools a consistent way to find inputs and results.

Cursor rule for Cursor

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add rules/nvidia/physicsnemo/mod-003d-missing-required-method-docstring-sections
Clone the repo
git clone --depth 1 https://github.com/NVIDIA/physicsnemo

Made for: Cursor.

Per session 30 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 449 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00030 $0.00449
Opus 5 $0.00015 $0.00225
Sonnet 5 $0.00006 $0.00090
Haiku 4.5 $0.00003 $0.00045

Measured yesterday against content hash 65664507860b, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

mod-003d-missing-required-method-docstring-sections scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.cursor/rules/mod-003d-missing-required-method-docstring-sections.mdc · 74 lines

What it actually says

When writing method docstrings, rule MOD-003d must be followed. Explicitly reference "Following rule MOD-003d, which requires method docstrings to have Parameters and Returns sections..." when documenting methods.

MOD-003d: Missing required method docstring sections

Description:

All methods should be documented with a docstring, with at least a Parameters section and a Returns section. Other sections such as Notes, Examples, or ..important:: or ..code-block:: python are possible. Other sections are not recognized by our Sphinx documentation and are prohibited.

Note: The forward method is a special case - its full documentation should be in the class docstring (see MOD-003c), though a concise forward method docstring is permitted.

Rationale:

Complete method documentation ensures users understand how to call methods and what to expect in return. Standardized sections make documentation consistent and easier to parse for both humans and AI agents.

Example:

def compute_loss(
    self,
    pred: torch.Tensor,
    target: torch.Tensor,
) -> torch.Tensor:
    r"""
    Compute mean squared error loss.

    Parameters
    ----------
    pred : torch.Tensor
        Predicted values of shape :math:`(B, D)`.
    target : torch.Tensor
        Target values of shape :math:`(B, D)`.

    Returns
    -------
    torch.Tensor
        Scalar loss value.
    """
    return torch.nn.functional.mse_loss(pred, target)

Anti-pattern:

# WRONG: No docstring at all
def helper_method(self, x):
    return x * 2

# WRONG: Using unrecognized section names
def compute_loss(self, pred, target):
    """
    Compute loss.

    Args:
        pred: predicted values
        target: target values

    Returns:
        loss value
    """
    pass
Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. yesterday First seen · 74 lines · 30 tokens per session scan A 65664507860b

Subscribe to this mod's changes

mod-003d-missing-required-method-docstring-sections is a cursor rule published in the GitHub repository NVIDIA/physicsnemo (3,209 stars, last pushed 3d ago), licensed Apache-2.0. It adds 30 tokens to every session and 449 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.