Dynamic update of Tools / Prompts and other explicit things to a client

[IvanMurzak]

Pre-submission Checklist

• I have verified this would not be more appropriate as a feature request in a specific repository
• I have searched existing discussions to avoid duplicates

Your Idea

Have some thoughts about dynamic capabilities which I would like to discuss. Would be happy to hear your thoughts.

There is the use case I imagine (and actually want to implement in my Unity-MCP server).

• MCP server has a Create Tool Tool that lets to create another tool.
• Client sends source code, name, description as arguments.
• MCP server rebuilds the list of capabilities in runtime.

As a result, client may extended features for itself on a fly.

In my particular Unity-MCP case, the MCP server don't need to recompile itself. It would ask Unity-MCP package in Unity Editor for the list of existed features. Unity is made with dotnet, it may host the csharp-sdk that would provide list of tools to the MCP server over TCP. Then the MCP server would talk to a client with updated list of tools.

Unity Editor is changing, and game developer may want to have drastically unique tools for their specific games. It sounds like a good idea at least to me to let a client to provide the source code of the tool. It is a common practice for a Unity Editor to recompile domain pretty often. The Unity-MCP package would immediately restart itself inside of Unity Editor environment and to re-establish TCP connection with MCP server.

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There is another reason of doing that. Lets say I am a Unity Developer who would like to use Unity-MCP solution in my custom game. And my game has a unique mechanic of level building which I would like to explicit to LLM. And to ask LLM to build the world for me using this unique mechanic. I may create my own C# function using csharp-sdk in my Unity project. Unity would recompile it immediately and the Unity-MCP package would send the updated list of capabilities to Unity-MCP Server.

Long story short, this is ability for developers to add capabilities without modifying MCP server. Because MCP server would be in unmodified space, because it is a package that would be installed into a project as a dependency.

Scope

• Protocol Specification
• SDK Features
• Documentation
• Developer Experience
• Other