OpenAI API MCP tools
TL;DR
OpenAI's API supports remote MCP tools whose results are returned through the Responses API. Exposed tools are controlled with filters such as allowed_tools to select a subset, and read_only to restrict a tool's mode.
Remote MCP tools
Remote MCP servers can be connected so their tools appear in the OpenAI API response. Only the API-supported subset of tools is available.
Filters
allowed_tools selects which tools are exposed, and read_only restricts the tool's mode. These filters narrow what the model can invoke.