The agent-template-adk / sdk-python supports propagating headers (esp. for auth) from Agents to ToolServers.
Update to new agent-template-adk 0.8.0 and add the propagate_headers option to the Agent CRD. Then pass this through the tool env var to the tool server.
See https://github.com/agentic-layer/sdk-python/blob/main/adk/README.md for reference.