MCP Tool Tutorial

How to build an MCP Tool.

Scripts → Tutorial | Concept | How-to Guide | Reference

Step 1: Create the MCP script

1. Navigate to Scripts → Classes

2. Click in the create a New Class button

3. In Create new Code, select MCPTool

4. Click OK

Step 2: Edit the Script

In the Script code, you can have multiple methods and they follow this format:

[McpServerTool, Description("<This is the question>")]
public string <MethodName> (
[Description("<Description of the parameter>")] <Parameters>)
{
	<Logic>

    <Return>
}

Example:

[McpServerTool, Description("Performs concatenation of two input text values.")]
public string Concat(
	[Description("The first text value to be used in the operation.")] string parameter1,
	[Description("The second text value to be used in the operation, concatenated after the first.")] string parameter2)
{
	return parameter1 + parameter2;
}

The logic can process the data and return it as a string, so the AI will receive it.

Step 3: Configure Claude AI

1. Have Claude AI Desktop downloaded

2. Go in Settings → Developer → Edit Config and select the ”claude_desktop_config.json”

3. This .json should have the following content:

   {
     "mcpServers": {
       "<SolutionName>": {
         "command": "<ProductPath>\\fx-10\\net8.0\\TMCPServerStdio\\TMCPServerStdio.exe",
         "args": [ "/host:127.0.0.1", "/port:<port>" ],
         "transport": "stdio"
       }
     }
   }

4. In the Developer setting it shoud show “running” and when you open a new chat in “Search and Tools” you will see the name of your solution there.

Step 4: Query in Claude AI

You can query any method in a Claude chat. e.g: “What is the tag value?” and it returns the value requested.

Besides the method you created in the script, you can ask general information about the solution, like:

• Get tag historian

• Get alarm online

• Get value

These tutorials provide simple, practical starting points for both MCP Tools focusing on real industrial scenarios while keeping complexity minimal for learning purposes.

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