Fix MCP tool UI display

[AnuradhaKaruppiah]

Description

Tools were not being displayed in the UI for mcp_client function groups. This PR fixes the issue by updating the separator from period to dunder.

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Summary by CodeRabbit

• Bug Fixes

  • Fixed parsing of fully-qualified and aliased function names so tool discovery and initialization are more consistent across contexts, reducing missing or misnamed tools at startup.

• Tests

  • Updated tests to reflect the improved naming/lookup behavior for group-qualified functions.

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[coderabbitai]

Walkthrough

Switches short-name extraction to use FunctionGroup.SEPARATOR/LEGACY_SEPARATOR, changes configured_short_names from set[str] to list[str], and applies the separator-aware logic consistently when building tool mappings in the FastAPI plugin worker and corresponding test(s).

Changes

Cohort / File(s)	Summary
FastAPI front-end worker src/nat/front_ends/fastapi/fastapi_front_end_plugin_worker.py	Add FunctionGroup import; change configured_short_names: set[str] → list[str]; derive short names by splitting on FunctionGroup.SEPARATOR or FunctionGroup.LEGACY_SEPARATOR (with fallback to full name) in pass_through_filter, tool construction, mapping, and total_tools calculation.
Tests updated for separator tests/nat/front_ends/fastapi/test_mcp_client_endpoint.py	Update test key construction to use FunctionGroup.SEPARATOR when forming alias-qualified function name used in group function map lookup.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

🚥 Pre-merge checks | ✅ 2 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 66.67% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title 'Fix MCP tool UI display' is concise, directly related to the main change (fixing MCP tool visibility in the UI), uses imperative mood, and is well within the 72-character limit.

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✨ Finishing touches

• 📝 Generate docstrings

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[willkill07]

Approving with minor feedback

[coderabbitai]

Actionable comments posted: 0

Caution

Some comments are outside the diff and can’t be posted inline due to platform limitations.

⚠️ Outside diff range comments (1)

tests/nat/front_ends/fastapi/test_mcp_client_endpoint.py (1)

146-150: Inconsistent separator usage with the first test.

This test still uses the legacy separator (.) in the function keys at lines 148-149, while test_mcp_client_tool_list_success_with_alias was updated to use FunctionGroup.SEPARATOR (__). For consistency with the PR's goal of switching to the new separator, consider updating these keys as well.

Suggested fix

     group_name = "mcp_math"
     group_instance = _GroupInstanceStub(client,
                                         {
-                                            f"{group_name}.calculator__add": _FnStub("Add"),
-                                            f"{group_name}.calculator__subtract": _FnStub("Subtract"),
+                                            f"{group_name}{FunctionGroup.SEPARATOR}calculator__add": _FnStub("Add"),
+                                            f"{group_name}{FunctionGroup.SEPARATOR}calculator__subtract": _FnStub("Subtract"),
                                         })

Alternatively, if testing legacy separator support is intentional, consider renaming the test or adding a comment to clarify this intent.

[AnuradhaKaruppiah]

/merge