Wraps any function as a tool with declaration metadata.

The func field accepts:

• An anonymous function (arity 1 or 2) — for runtime use
• An MFA tuple {Module, :function, extra_args} — compile-time safe
• A plain MF tuple {Module, :function} — shorthand for {Module, :function, []}

MFA tuples are called as Module.function(ctx, args, ...extra_args) (arity 2+) or Module.function(args, ...extra_args) if the function has no context parameter.

Examples

# Anonymous function (runtime only)
tool = ADK.Tool.FunctionTool.new(:greet,
  description: "Greet someone",
  func: fn _ctx, %{"name" => name} -> {:ok, "Hello, #{name}!"} end,
  parameters: %{
    type: "object",
    properties: %{name: %{type: "string"}},
    required: ["name"]
  }
)

# MFA tuple (compile-time safe, works in Plug init/1)
tool = ADK.Tool.FunctionTool.new(:greet,
  description: "Greet someone",
  func: {MyApp.Tools, :greet},
  parameters: %{
    type: "object",
    properties: %{name: %{type: "string"}},
    required: ["name"]
  }
)