A batch job for assessor PDFs needs mid-request live MCP parcel lookups. What limitation applies?
Select an answer to reveal the explanation.
Short Explanation
Batch tickets don't chat mid-flight with live tools—like a sealed mailbag. If you need MCP parcel lookups during the request, don't use Batches that way.
Full Explanation
A batch job that must perform mid-request live MCP parcel lookups hits a hard platform limitation: the Message Batches API does not support multi-turn tool calling within a single request. Batch items are submitted as discrete, largely non-interactive units; they are not a substitute for an agent loop that calls MCP tools, observes results, and continues reasoning in the same turn chain. Live assessor lookups therefore belong on interactive patterns, or lookups must be resolved before batch submission and passed in as static context. Claiming batches always support unlimited multi-turn tool calling inside one request is false and leads to designs that fail at runtime. Asserting MCP tools can only run inside batches, never in interactive sessions, inverts the actual constraint. Saying live MCP lookups require deleting custom_id from every batch item invents an unrelated requirement—custom_id remains valuable for tracking and retry, and deleting it does not unlock multi-turn tools. Exam caveat: separate precomputation of tool results from true mid-request tool use when planning civic batch extracts. Operational check: if a PDF extract needs live parcel MCP data, either enrich offline before enqueueing the batch or run an interactive worker; verify batch requests do not assume tool round-trips mid-item.