Module six of the Hermes Agent Masterclass explains how tools and MCP servers extend Hermes’s functionality by enabling actions like file handling, code execution, and external system integration, while emphasizing security through controlled tool access and sandboxing. It also demonstrates registering native and MCP tools, including a custom stock price checker, and highlights bidirectional MCP support for seamless interoperability with platforms like Blender and VS Code.
In module six of the Hermes Agent Masterclass, the focus is on tools and MCP (Model Context Protocol) servers, which are essential for extending the capabilities of the Hermes agent beyond simple text-based interactions. Tools enable the agent to perform actions like reading files, executing code, browsing the web, analyzing images, and interacting with external systems. The video explains what tools are, how they are registered and managed within Hermes, and how MCP servers can be consumed or exposed to expand the agent’s functionality. The importance of controlling the tool surface to maintain security and trust is emphasized throughout.
The video breaks down tools into three components: the function (actual code execution), the schema (description and parameters visible to the model), and the registry (which links the schema and handler so the tool can be called). Hermes manages tool execution by receiving structured requests from the model and running the corresponding functions, returning results in JSON format. This design ensures that tool failures do not crash the agent but instead provide recoverable error information. Hermes includes a built-in registry with around 70 tools organized into logical tool sets like file, terminal, web, and vision, which can be selectively enabled or disabled to control the agent’s accessible capabilities.
Surface control is a key security feature, allowing users to scope which tools and tool sets the agent can access during a session or persistently via configuration files or the web dashboard. Sandboxing further restricts where tools execute, such as limiting actions to read-only operations in untrusted contexts. The video also covers different terminal backends for tool execution, including local, Docker, and SSH environments, and highlights the use of approval models to gate risky actions. This layered approach ensures that Hermes operates safely and transparently, with visible tool calls during interactions.
MCP servers are introduced as an adaptive layer that allows Hermes to connect to external capabilities without core code changes. MCP servers register their tools dynamically, which appear alongside native tools in Hermes, enabling flexible and secure integration. The video demonstrates adding an MCP server for Blender, showing how Hermes can drive Blender to create 3D models via tool calls. It also explains how to expose Hermes itself as an MCP server, allowing other clients like VS Code to interact with Hermes tools and services. This bidirectional MCP support enhances Hermes’s interoperability with various platforms.
Finally, the video walks through authoring a custom native tool—a stock price checker using the FinHub API. It covers the Python implementation, schema definition, registration, and integration into Hermes’s tool sets. The tool successfully retrieves real-time stock prices when queried, illustrating how users can extend Hermes with domain-specific functions. The module concludes with a recap of skills versus tools, tool management, MCP server usage, and surface control, setting the stage for the next module on automation and scheduled tasks. Overall, this session equips users with the knowledge to safely and effectively expand Hermes’s capabilities through tools and MCP servers.