We want to use Amazon Wisdom for multiple clients. Can we restrict agent(s) access to Amazon Wisdom content:

You can now create multiple Wisdom Domain and each can have different KB articles. Then in the call flow, you can choose which Wisdom domain to use for a call. Example would be different queue could use different Wisdom Domain

https://docs.aws.amazon.com/connect/latest/adminguide/wisdom.html

In Amazon Connect Wisdom, access to content depends on the permissions that the agent has in AWS Identity and Access Management (IAM). If an agent has the necessary permissions to access Wisdom, they can potentially see all the content in the service.

However, you may use AWS IAM policies and Amazon Resource Names (ARNs) for granularity in terms of access control. Depending on your use case, you might want to create custom IAM policies that allow or deny access to specific Wisdom APIs. However, note that these permissions apply to API operations and do not inherently restrict access to specific customer content within Wisdom.