Class McpSchemaAttribute

Marks a static method as providing a custom input schema for an MCP tool. Use this when a tool takes JObject parameters and needs a schema more specific than the default.

Inheritance
object
Attribute
McpSchemaAttribute
Implements
Inherited Members
Namespace: Unity.AI.MCP.Editor.ToolRegistry
Assembly: Unity.AI.MCP.Editor.dll
Syntax
[AttributeUsage(AttributeTargets.Method, AllowMultiple = false)]
public class McpSchemaAttribute : Attribute, _Attribute
Remarks

The schema method must:

  • Be public static
  • Return an object representing the JSON schema
  • Have no parameters

The ToolName must match the name used in the [McpTool] attribute. This attribute is only needed for tools using JObject parameters; typed parameter tools automatically generate schemas from the parameter type.

Examples
[McpTool("custom_action", "Performs a custom action")]
public static object CustomAction(JObject params)
{
    // Tool implementation
}

[McpSchema("custom_action")]
public static object CustomActionSchema()
{
    return new
    {
        type = "object",
        properties = new
        {
            action = new { type = "string", enum = new[] { "create", "delete" } },
            target = new { type = "string", description = "Target to act upon" }
        },
        required = new[] { "action" }
    };
}

Constructors

McpSchemaAttribute(string)

Creates a schema attribute linking this method to an MCP tool.

Declaration
public McpSchemaAttribute(string toolName)
Parameters
Type Name Description
string toolName

The name of the tool this schema is for (must match the [McpTool] name exactly)
Exceptions
Type Condition
ArgumentException

Thrown if toolName is null or empty

Properties

ToolName

Gets the name of the tool this schema method provides the input schema for. Must exactly match the name used in the corresponding [McpTool] attribute.

Declaration
public string ToolName { get; }
Property Value
Type Description
string

Implements