docs: fix docstring parameter name, add missing Args and Raises secti…

[chhayankjain]

Description

Fix several docstring issues across loss functions in monai/losses/:

• barlow_twins.py: fix parameter name typo (lamb → lambd) in Args section
• nacl_loss.py: add missing kernel_ops arg, update distance_type/alpha with defaults, add Raises section
• multi_scale.py: add missing reduction arg, add Raises section
• ds_loss.py: add forward docstring with Args and Raises section
• perceptual.py: add Raises section to class docstring

No functional changes.

Types of changes

• Non-breaking change (fix or new feature that would not break existing functionality).

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

Run ID: 879bec44-977e-4226-b314-b4a87a3ef642

📥 Commits

Reviewing files that changed from the base of the PR and between 23266b7 and e90190e.

📒 Files selected for processing (5)

• monai/losses/barlow_twins.py
• monai/losses/ds_loss.py
• monai/losses/multi_scale.py
• monai/losses/nacl_loss.py
• monai/losses/perceptual.py

✅ Files skipped from review due to trivial changes (5)

• monai/losses/barlow_twins.py
• monai/losses/multi_scale.py
• monai/losses/nacl_loss.py
• monai/losses/ds_loss.py
• monai/losses/perceptual.py

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📝 Walkthrough

Walkthrough

This PR updates docstrings in five MONAI loss modules: monai/losses/barlow_twins.py, ds_loss.py, multi_scale.py, nacl_loss.py, and perceptual.py. Changes correct a parameter name in BarlowTwinsLoss and expand docstrings to document arguments, supported values, and raised exceptions (including DeepSupervisionLoss.forward, MultiScaleLoss.init, NACLLoss.init, and PerceptualLoss). No runtime behavior, control flow, or public API signatures were changed.

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~3 minutes

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	Title accurately summarizes the main changes: fixing docstring parameter name and adding missing Args and Raises sections across loss files.
Description check	✅ Passed	Description covers all file changes with specific details about docstring fixes. Template compliance is good with description and types of changes completed.
Docstring Coverage	✅ Passed	Docstring coverage is 83.33% which is sufficient. The required threshold is 80.00%.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[coderabbitai]

Actionable comments posted: 2

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@monai/losses/ds_loss.py`:
- Around line 72-79: The forward method's docstring in monai/losses/ds_loss.py
is missing a Returns section; update the docstring for the forward function
(method name: forward, class: DSLoss/DeeplySupervisedLoss if present) to include
a Returns section that states it returns a torch.Tensor (describe shape/meaning,
e.g., scalar loss tensor or per-sample loss tensor) and any dtype/device
expectations, and keep the existing Args/Raises content unchanged so readers
know what the function returns.

In `@monai/losses/multi_scale.py`:
- Around line 64-66: The docstring for the function in
monai/losses/multi_scale.py documents a ValueError only for invalid ``kernel``
but omits that invalid ``reduction`` values also raise ValueError; update the
Raises section to list ValueError for unsupported ``reduction`` values (e.g.,
describe when ``reduction`` is not one of the accepted options) so users know
both error conditions raised by the function that uses the ``reduction``
parameter.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

Run ID: e8f36a6b-375a-47a2-9839-f7a39b7703c1

📥 Commits

Reviewing files that changed from the base of the PR and between 586dea1 and 151f509.

📒 Files selected for processing (5)

• monai/losses/barlow_twins.py
• monai/losses/ds_loss.py
• monai/losses/multi_scale.py
• monai/losses/nacl_loss.py
• monai/losses/perceptual.py