use mcp tool listing recorded in previous response if present #3106
Description
🚀 Describe the new functionality needed
As described by https://platform.openai.com/docs/guides/tools-remote-mcp#step-1-getting-the-list-of-tools-from-the-mcp-server, OpenAIs implementation of the Responses API only relists tools for a given MCP server if there is no previous listing already in context.
The enhancement requested is that where the implied input includes an mcp_list_tools item, whether explicitly or implicitly via the inclusion of any prior response linked by previous_response_id, that this recorded list is used in place of making a call to the MCP server. This avoids the overhead of listing tools for every create response request in a stateful sequence.
💡 Why is this needed? What if we don't build it?
Using MCP tools on sequential requests to create responses is very slow (much slower than using the Agents API for example, where the tool listing is done once on agent creation).
Other thoughts
No response