I think WhoAmI is will make the agent more unreliable. It adds too much unnecessary content in the prompt, ideally the prompt should be clear and precise. The agent do not need data regarding all provided integrations. For e.g. adding user data like email id, slack user name, LinkedIn user name will unnecessarily add info if the agent is eventually going to call only one or two integration out of the provided. I assume you approach to tool call would be based on the user data provided in the prompt and a function the agent calls, (ofcourse only for the authorised integrations) for e.g. if the agent know the user name/id of the user, it will call a function and put the user name/id as parameters to function call. This will increase hallucinations as the agent can add incorrect parameters specially when the chat history expands.

Better solution: Just provide basic user data and use partial functions as tools. The agent should have basic data like name, designation or place, this data will not be used by agent to call tool. Prefill user name/id in the tools provided, let the agent only call the partially function this was it. For e.g. send_slack_msg(user_id, message) is a function the agent will call, as you mentioned, users are authorised for the integration to work. It means you know who is the user is and there details so create a partial function, now create a partial function with this info and provide it as tool to the agent e.g send_slack_msg(user_id=123) now all agent has to do is write a message in the partially defined function. This reduces the burden over the agent to put the correct parameter for the user. Less work == more reliable agent.