Motivation and Context

The fix in #3563 (commit 184ee9d) addressed instructions being dropped in AzureAIAgentClient (Chat API), but the same bug existed in AzureAIClient (Responses API).

In _get_agent_reference_or_create(), the code was reading instructions from run_options:

for instructions in [messages_instructions, run_options.get("instructions")]

But the base class excludes instructions from run_options, so it should be read from chat_options instead (same pattern used for response_format on lines 351-352).

The fix: changed _client.py to read instructions from chat_options:

for instructions in [messages_instructions, chat_options.get("instructions") if chat_options else None]

• Updated existing test to pass instructions via chat_options
• Added new test test_agent_creation_with_instructions_from_chat_options to verify instructions are correctly passed

Description

• Fixes Python: [Bug] Instructions not passed to Azure AI Foundry agents - wrong variable in commit 184ee9d5 #3622

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.