Vertex AI Agent Tools: Connect Your Agent to APIs with ADK and Terraform 🔌

An agent without tools is just a chatbot. ADK gives your Vertex AI agent five ways to connect to APIs - function tools, OpenAPI tools, MCP tools, built-in tools, and agent-as-tool. Here's how to wire them up with Terraform provisioning the infrastructure. In the previous post, we deployed a Vertex AI agent with ADK and Agent Engine. It can reason and hold conversations, but without tools it can only generate text. Ask it to check a stock price or create a ticket, and it describes what it would do instead of doing it. ADK's tool ecosystem is where GCP agents shine. Unlike AWS where action groups require Lambda functions and OpenAPI schemas as separate resources, ADK lets you define tools as Python functions, OpenAPI specs, MCP servers, or even other agents - all in the same codebase. The agent decides which tool to use based on the user's request, and ADK handles the execution. Terraform provisions the infrastructure; Python defines the capabilities. 🎯 🔧 Five Tool Types in ADK Tool Ty