---
schema_version: "newruntime-agent-readable-v0.2"
type: "raw_signal"
stable_id: "signal:claude-opus-5-prompt-contracts"
id: "nr-85922586-db8b-4ae9-b99b-485e14a80cc0"
slug: "claude-opus-5-prompt-contracts"
title: "Claude Opus 5 Turns Prompting Into Harness Calibration"
description: "Anthropic's Opus 5 prompting guide shows model upgrades changing the harness contract: verbosity, progress updates, scope, subagents, verification, and thinking mode all need retuning."
retrieval_nugget: "Anthropic's Opus 5 prompting guide shows model upgrades changing the harness contract: verbosity, progress updates, scope, subagents, verification, and thinking mode all need retuning. This official-source record adds evidence that model upgrades are no longer just capability changes; they force prompt, effort, delegation, and verification policies to move with the runtime. Novelty is structural; verification is source-inspected."
observed_at: "2026-07-28"
record_date: "2026-07-28"
date_kind: "observed_at"
why_it_matters: "This official-source record adds evidence that model upgrades are no longer just capability changes; they force prompt, effort, delegation, and verification policies to move with the runtime."
novelty: "structural"
verification_level: "source-inspected"
signal_type: "operating-model"
evidence_kind: "primary-source"
status: "published"
source_platform: "newsletter"
source_record_id: "85922586-db8b-4ae9-b99b-485e14a80cc0"
source_url: "https://platform.claude.com/docs/en/build-with-claude/prompt-engineering/prompting-claude-opus-5"
topics: ["claude","prompting","agent-harnesses"]
entities: ["Anthropic","Claude"]
related_patterns: ["harness-architecture-outlives-model-choice","skills-become-portable-capability-layer","verification-bandwidth-is-the-scarce-resource"]
source_urls: ["https://platform.claude.com/docs/en/build-with-claude/prompt-engineering/prompting-claude-opus-5"]
import_batch: "newsletter-85922586-db8b-4ae9-b99b-485e14a80cc0"
routes: {"html":"https://newruntime.com/signals/claude-opus-5-prompt-contracts/","markdown":"https://newruntime.com/signals/claude-opus-5-prompt-contracts.md","json":"https://newruntime.com/signals/claude-opus-5-prompt-contracts.json"}
source_format: "editorial-inbox-sanitized-batch"
---

# Claude Opus 5 Turns Prompting Into Harness Calibration

## Retrieval answer

Anthropic's Opus 5 prompting guide shows model upgrades changing the harness contract: verbosity, progress updates, scope, subagents, verification, and thinking mode all need retuning. This official-source record adds evidence that model upgrades are no longer just capability changes; they force prompt, effort, delegation, and verification policies to move with the runtime. Novelty is structural; verification is source-inspected.

## Observation

Anthropic's Opus 5 prompting guide shows model upgrades changing the harness contract: verbosity, progress updates, scope, subagents, verification, and thinking mode all need retuning.

## Why it matters

This official-source record adds evidence that model upgrades are no longer just capability changes; they force prompt, effort, delegation, and verification policies to move with the runtime.

## Provenance

This public record is a sanitized New Runtime Editorial Inbox signal. Linked source_urls carry the publishable evidence boundary; private discovery provenance stays internal.