AGUI208

Severity: info · Group: Tool calls · Checked in: core · Since: 0.x

Message: TOOL_CALL_START parentMessageId '{parentMessageId}' matches no message observed in this stream

Spec grounding

The optional parentMessageId allows linking the tool call to a specific message in the conversation, providing context for why the tool is being used.

Source: https://docs.ag-ui.com/concepts/events#toolcallstart

The spec is not fully explicit here; the ambiguity is tracked as SQ-11 and the severity is capped accordingly (false positives are worse than false negatives).

Example

A violating stream from the corpus (spec/fixtures/invalid/AGUI208-unknown-parent-message-id):

{"type":"RUN_STARTED","threadId":"thread_001","runId":"run_001","timestamp":1755300015900}
{"type":"TOOL_CALL_START","toolCallId":"call_001","toolCallName":"get_weather","parentMessageId":"msg_ghost","timestamp":1755300016000}
{"type":"TOOL_CALL_END","toolCallId":"call_001","timestamp":1755300016100}
{"type":"RUN_FINISHED","threadId":"thread_001","runId":"run_001","outcome":{"type":"success"},"timestamp":1755300016200}

Expected findings:

• info AGUI208 at event 1 — TOOL_CALL_START parentMessageId 'msg_ghost' matches no message observed in this stream