feat: wrap FastMCP tools as AskUI Tool via Tool.from_mcp_tool

[mlikasam-askui]

Summary

Adds Tool.from_mcp_tool() so a FastMCP Tool can be used as an AskUI Tool in the same flows as hand-written tools (for example ToolCollection). Name, description, and JSON schema come from the FastMCP tool; execution delegates to its callable.

What changed

• Tool.from_mcp_tool(mcp_tool, name_prefix=None) — factory that returns an adapter implementing AskUI’s Tool contract.
• _McpToolAdapter — forwards __call__ to mcp_tool.fn, with optional name_prefix on the exposed tool name.
• Result normalization — _convert_from_mcp_tool_call_result maps return values to AskUI-friendly primitives:
  • str — unchanged
  • McpTextContent — text
  • McpImageContent — PIL image via base64_to_image
  • list / tuple of the above — same structure, items converted per element
• McpToolAdapterException — raised when the wrapped tool returns an unsupported type or has no callable, with the tool name included for debugging.

Usage

from fastmcp.tools import Tool as FastMcpTool
from askui.models.shared.tools import Tool

mcp_tool = FastMcpTool.from_function(fn, name="my_tool", description="...")
askui_tool = Tool.from_mcp_tool(mcp_tool)

Notes

• Complements existing Tool.to_mcp_tool() for the opposite direction (AskUI → FastMCP).