fix(nemo-agents): add support for translation of mcp/skills/tools from agent.yaml to FabricConfig

[mmogallapalli]

Summary

This PR extends the Platform-owned nemo-agents-spec-v1 config translation for Fabric-backed NeMo Agents.

The main boundary remains:

Platform agent.yaml -> AgentConfig -> typed in-memory FabricConfig

This change adds support for translating shared Platform config fields that have direct FabricConfig targets today: skills, mcp, and tools.

Changes

• Added typed AgentConfig models for shared capability sections:
  • skills.paths
  • mcp.servers
  • tools.blocked
• Updated the Fabric translator to pass those sections through to FabricConfig.
• Kept prompt settings harness-specific for now, since Fabric does not currently expose a shared top-level prompts field.
• Added explicit rejection for non-empty top-level prompts during Fabric translation so prompt config is not silently ignored.
• Updated the example agent.yaml with neutral shared capability sections.
• Updated the example README to describe the Platform/Fabric boundary for shared fields and prompt settings.
• Added focused unit coverage for config validation and Fabric translation.

Out Of Scope

• A shared Platform prompt contract.
• Per-turn prompt overrides.
• Full translation of every optional FabricConfig field.
• Runtime/session lifecycle changes.
• NAT-specific harness translation for shared fields.

Those should be handled once the RFC 121/122 object shapes and runtime story are finalized.

Validation

Passed:

uv run --frozen pytest plugins/nemo-agents/tests/unit/test_agent_config.py plugins/nemo-agents/tests/unit/test_fabric_translator.py
tools/lint/lint-python-style.sh plugins/nemo-agents/src/nemo_agents_plugin/agent_config.py plugins/nemo-agents/src/nemo_agents_plugin/fabric/translator.py plugins/nemo-agents/tests/unit/test_agent_config.py plugins/nemo-agents/tests/unit/test_fabric_translator.py

Result:

26 passed
All checks passed

Summary by CodeRabbit

• New Features

  • Added support for configuring shared skills, MCP servers, and tools in agent configurations.
  • Added validation for these capability settings and translated them into Fabric configurations.
  • Added harness-specific system prompt configuration.

• Bug Fixes

  • Top-level prompt settings are now rejected with guidance to configure prompts under the selected harness.

• Documentation

  • Updated configuration guidance for shared capability fields and harness-specific prompts.

[coderabbitai]

📝 Walkthrough

Walkthrough

Agent configuration now uses typed skills, mcp, and tools sections, translates them into FabricConfig, and rejects unsupported top-level prompts. The example configuration moves the system prompt into the codex harness and adds coverage for parsing and translation.

Changes

Shared capability translation

Layer / File(s)	Summary
Typed capability configuration plugins/nemo-agents/src/nemo_agents_plugin/agent_config.py, plugins/nemo-agents/examples/nemo-agent-config/*, plugins/nemo-agents/tests/unit/test_agent_config.py	Adds strict Pydantic models for skills, MCP, and tools; updates the example YAML and README; validates defaults and populated sections.
Fabric translation and validation plugins/nemo-agents/src/nemo_agents_plugin/fabric/translator.py, plugins/nemo-agents/tests/unit/test_fabric_translator.py	Maps shared capability sections into Fabric types and rejects top-level prompts with dedicated test coverage.

Sequence Diagram(s)

sequenceDiagram
  participant AgentYAML
  participant AgentConfig
  participant translate_agent_config
  participant FabricConfig
  AgentYAML->>AgentConfig: Load skills, mcp, and tools
  AgentConfig->>translate_agent_config: Provide validated configuration
  translate_agent_config->>translate_agent_config: Reject top-level prompts
  translate_agent_config->>FabricConfig: Translate capability sections

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Possibly related PRs

• NVIDIA-NeMo/nemo-platform#701: Adds groundwork used by the expanded Fabric translation.
• NVIDIA-NeMo/nemo-platform#761: Refactors the translator modified by this change.
• NVIDIA-NeMo/nemo-platform#838: Consumes the translated configuration in Fabric-backed invocation.

Suggested labels: feat

Suggested reviewers: stefan-kickoff, mikeknep

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately summarizes the main change: translating skills, mcp, and tools from agent.yaml into FabricConfig.
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.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch mmogallapall/aircore-946-translate-shared-platform-agent-config-fields-into

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[coderabbitai]

🧹 Nitpick comments (2)

plugins/nemo-agents/examples/nemo-agent-config/README.md (1)

14-16: 📐 Maintainability & Code Quality | 🔵 Trivial | ⚡ Quick win

Keep this page a HOW-TO.

Move the shared-field contract explanation to a reference page and link it here. As per coding guidelines, “Each documentation page should fit ONE Diataxis quadrant.”

Source: Coding guidelines

plugins/nemo-agents/src/nemo_agents_plugin/fabric/translator.py (1)

99-116: 📐 Maintainability & Code Quality | 🔵 Trivial | ⚡ Quick win

Type these helpers with Fabric models. _skills_config, _mcp_config, and _tools_config should return fabric.SkillConfig | None, fabric.McpConfig | None, and fabric.ToolsConfig | None instead of Any.

🤖 Prompt for 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.

In `@plugins/nemo-agents/src/nemo_agents_plugin/fabric/translator.py` around lines
99 - 116, Update the return annotations of _skills_config, _mcp_config, and
_tools_config to use fabric.SkillConfig | None, fabric.McpConfig | None, and
fabric.ToolsConfig | None respectively, replacing Any while preserving their
existing None handling and Fabric model construction.

Source: Coding guidelines

🤖 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.

Nitpick comments:
In `@plugins/nemo-agents/src/nemo_agents_plugin/fabric/translator.py`:
- Around line 99-116: Update the return annotations of _skills_config,
_mcp_config, and _tools_config to use fabric.SkillConfig | None,
fabric.McpConfig | None, and fabric.ToolsConfig | None respectively, replacing
Any while preserving their existing None handling and Fabric model construction.

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Enterprise

Run ID: 61632f57-2af5-4c28-904a-b188c3012f9b

📥 Commits

Reviewing files that changed from the base of the PR and between 009588a and a95c5b8.

📒 Files selected for processing (6)

• plugins/nemo-agents/examples/nemo-agent-config/README.md
• plugins/nemo-agents/examples/nemo-agent-config/agent.yaml
• plugins/nemo-agents/src/nemo_agents_plugin/agent_config.py
• plugins/nemo-agents/src/nemo_agents_plugin/fabric/translator.py
• plugins/nemo-agents/tests/unit/test_agent_config.py
• plugins/nemo-agents/tests/unit/test_fabric_translator.py

[AjayThorve]

Looks good

[github-actions]

Suite	Lines Covered	Line Rate	Branch Rate
Unit Tests	27158/34869	77.9%	62.1%
Integration Tests	15970/33581	47.6%	20.0%