Python: Fix declarative package powerfx import crash and response_format kwarg error

[moonbox3]

Motivation and Context

• Fix unconditional from powerfx import Engine import in _declarative_base.py that makes the entire agent_framework_declarative package unusable without .NET installed.
  Wraps the import in try/except (ImportError, RuntimeError) matching the existing pattern in _models.py and _state.py.
• Fix _create_agent_with_provider passing response_format as a direct keyword argument to provider.create_agent(), which fails on providers with strict signatures (e.g.
  AzureAIProjectAgentProvider). Moves response_format into default_options where all providers expect it.
• Fix declarative workflows not forwarding kwargs from workflow.run() to agent tool invocations, which makes sure @tool functions receive custom context data (e.g., user tokens, service configs) passed by the caller.

Description

• Fixes .NET: Python: [Bug]: powerfx should be imported conditionally in agent_framework_declarative #3817
• Fixes Python: [Bug]: MCP tool YAML has a bug in create_agent_from_yaml_async #3523
• Fixes Python: [Bug]: Declarative workflows don't forward kwargs to agent tools #3562

Contribution Checklist

• The code builds clean without any errors or warnings
• The PR follows the Contribution Guidelines
• All unit tests pass, and I have added new tests where possible
• Is this a breaking change? If yes, add "[BREAKING]" prefix to the title of the PR.

[markwallace-microsoft]

Python Test Coverage Report •

File	Stmts	Miss	Cover	Missing
TOTAL	16787	2110	87%

report-only-changed-files is enabled. No files were changed during this commit :)

Python Unit Test Overview

Tests	Skipped	Failures	Errors	Time
4017	225 💤	0 ❌	0 🔥	1m 10s ⏱️

[Copilot]

Pull request overview

Fixes two Python declarative-agent creation failures: (1) importing agent_framework_declarative without a working .NET runtime due to an unconditional powerfx import, and (2) async provider-based agent creation failing on strict provider signatures due to passing response_format as an unexpected kwarg.

Changes:

• Wrap from powerfx import Engine in _declarative_base.py with try/except (ImportError, RuntimeError) and gate evaluation when PowerFx isn’t available.
• Pass structured output configuration via default_options={"response_format": ...} instead of a direct response_format= kwarg in provider-based agent creation.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
python/packages/declarative/agent_framework_declarative/_workflows/_declarative_base.py	Makes PowerFx import conditional and adds runtime handling when the engine is unavailable.
python/packages/declarative/agent_framework_declarative/_loader.py	Fixes provider creation to avoid strict-signature kwarg errors by moving response_format into default_options.

[Copilot]

Pull request overview

Copilot reviewed 6 out of 6 changed files in this pull request and generated 4 comments.