Fix AG-UI backend tool rendering example — broken imports and API changes

[Ashutosh0x]

Fixes #406

Problem

The AG-UI backend tool rendering example in backend-tool-rendering.md throws an ImportError when executed:

from agent_framework import Agent, ToolCallContent, ToolResultContent ImportError: cannot import name 'ToolCallContent' from 'agent_framework'

The ToolCallContent and ToolResultContent classes were removed/renamed in recent agent-framework releases, breaking the documented example.

Changes

1. Removed broken imports — ToolCallContent and ToolResultContent no longer exist in agent_framework. Changed import to just from agent_framework import Agent

2. Fixed AGUIChatClient constructor — Changed from positional server_url to keyword endpoint=server_url to match current API

3. Replaced isinstance() checks with getattr() type-string checking — More resilient to API changes:

   • isinstance(content, ToolCallContent) → getattr(content, 'type', '') == 'function_call'
   • isinstance(content, ToolResultContent) → content_type in {'function_result', 'tool_result'}

4. Added null guard — update.contents → (update.contents or []) to prevent TypeError on None

Testing

Verified the corrected code follows the working pattern reported by @mjmadhu in #406.

Context

I'm an active contributor to the microsoft/agent-framework repo (PRs #6642 and #6643) and encountered these same API changes while working on the Python hosting stack.

[learn-build-service-prod]

Learn Build status updates of commit 24d478a:

⚠️ Validation status: warnings

File	Status	Preview URL	Details
agent-framework/get-started/workflows.md	⚠️Warning		Details
agent-framework/integrations/ag-ui/backend-tool-rendering.md	✅Succeeded

agent-framework/get-started/workflows.md

• Line 64, Column 1: [Warning: invalid-code] The code snippet "~/../agent-framework-code/python/samples/01-get-started/05_first_workflow.py" could not be found.
• Line 68, Column 1: [Warning: invalid-code] The code snippet "~/../agent-framework-code/python/samples/01-get-started/05_first_workflow.py" could not be found.

For more details, please refer to the build report.

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