{"record":{"id":"65bad1583d24ac13","repo":"rohitg00/ai-engineering-from-scratch","slug":"task-result-is-valid-only-for-tools-call","errorCode":null,"errorMessage":"task result is valid only for tools/call","messagePattern":"task result is valid only for tools/call","errorType":"validation","errorClass":"ProtocolViolation","httpStatus":null,"severity":"error","filePath":"phases/13-tools-and-protocols/31-mcp-conformance-versioning-and-operations/code/main.py","lineNumber":305,"sourceCode":"            raise ProtocolViolation(\"completion/complete requires a completion object\")\n        values = completion.get(\"values\")\n        if not isinstance(values, list) or any(not isinstance(value, str) for value in values):\n            raise ProtocolViolation(\"completion.values must be an array of strings\")\n        if len(values) > 100:\n            raise ProtocolViolation(\"completion.values must contain at most 100 entries\")\n        total = completion.get(\"total\")\n        if total is not None and (\n            isinstance(total, bool) or not isinstance(total, int) or total < len(values)\n        ):\n            raise ProtocolViolation(\"completion.total must be an integer at least values length\")\n        has_more = completion.get(\"hasMore\")\n        if has_more is not None and not isinstance(has_more, bool):\n            raise ProtocolViolation(\"completion.hasMore must be a boolean\")\n\n    if result_type != \"task\":\n        return\n    if method != \"tools/call\":\n        raise ProtocolViolation(\"task result is valid only for tools/call\")\n    required_strings = (\"taskId\", \"status\", \"createdAt\", \"lastUpdatedAt\")\n    for field in required_strings:\n        if not isinstance(result.get(field), str) or not result[field]:\n            raise ProtocolViolation(f\"task result requires non-empty {field}\")\n    if result[\"status\"] not in {\"working\", \"input_required\", \"completed\", \"cancelled\", \"failed\"}:\n        raise ProtocolViolation(\"task result has an unknown status\")\n    if \"ttlMs\" not in result:\n        raise ProtocolViolation(\"task result requires ttlMs\")\n    ttl_ms = result[\"ttlMs\"]\n    if ttl_ms is not None and (\n        isinstance(ttl_ms, bool) or not isinstance(ttl_ms, int) or ttl_ms < 0\n    ):\n        raise ProtocolViolation(\"task result ttlMs must be null or a non-negative integer\")\n    poll_interval = result.get(\"pollIntervalMs\")\n    if poll_interval is not None and (\n        isinstance(poll_interval, bool) or not isinstance(poll_interval, int) or poll_interval < 0\n    ):\n        raise ProtocolViolation(\"task result pollIntervalMs must be a non-negative integer\")","sourceCodeStart":287,"sourceCodeEnd":323,"githubUrl":"https://github.com/rohitg00/ai-engineering-from-scratch/blob/39ea8a1c6d0b61f071226eff7ede4d4105fed820/phases/13-tools-and-protocols/31-mcp-conformance-versioning-and-operations/code/main.py#L287-L323","documentation":"Error \"task result is valid only for tools/call\" thrown in rohitg00/ai-engineering-from-scratch.","triggerScenarios":"Thrown at phases/13-tools-and-protocols/31-mcp-conformance-versioning-and-operations/code/main.py:305 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":[],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"39ea8a1c6d0b61f071226eff7ede4d4105fed820","analyzedAt":"2026-08-26T03:13:46.626Z","schemaVersion":2},"datasetVersion":"2026-08-26T07:17:17.940Z"}