Clarify validation before tool approval

[trymhaak]

Summary

Clarify that human approval is scoped to the exact tool call in the approval request.

The added note tells readers to:

• validate the requested function name and arguments against the application's allowlist and current authorization policy;
• require a new approval if the tool call changes.

This keeps the guidance next to the existing description of ToolApprovalRequestContent / function_approval_request without changing any language-specific API examples.

Validation

• confirmed the target paragraph occurs exactly once on current upstream main
• git diff --check passes
• change is limited to one three-line Microsoft Learn callout

[learn-build-service-prod]

Learn Build status updates of commit d7b337d:

✅ Validation status: passed

File	Status	Preview URL	Details
agent-framework/workflows/human-in-the-loop.md	✅Succeeded

For more details, please refer to the build report.