Agent-written creatives, deterministic claim checks

AI generated ad creative is allowed to draft. It is not allowed to invent proof. Variant copy stays claim-guarded until landing-page claim extraction exists. Freeform planner claim_sources are not accepted as evidence.

That rule shipped in the May 2026 assistant correction. The planner can write creative variant ideas from the user prompt, the account snapshot, and intent. It does not first prove claims through the destination crawler, the policy classifier, attachment analysis, or a structured claim extraction step. Until that extraction exists, creative variant rows stay deterministic and claim-guarded.

What "claim-guarded" means in practice

A variant can repeat product facts we already publish: one account; dashboard, API, CLI, and MCP; no DSP setup; no insertion order; no sales call; creative tests; real reporting. It can name the angle promise the campaign is actually testing.

A variant cannot treat the model's own citation list as a stored evidence record. It cannot write a benchmark we did not measure. It cannot promise performance, inventory access, or conversion lift. It cannot borrow a Supply Bench completion as if it were a product signup result.

When landing-page claim extraction exists, creative_variant_candidates.claim_sources should point at real stored claim records from the crawler and classifier, not at freeform model text. That step is planned. It is not the current path.

Why this belongs in Ideas, not in a victory lap

The point of agent-written creatives is speed inside one promise. The point of the guard is that leftover inventory already rewards exaggerated banners. If the model writes a prize or a scarcity line we will not fulfill, we manufacture the same bad CTR we are trying to measure on /sb. Curiosity that still tells the truth is the consumer version of this rule. The product version is: keep the sentence inside the angle and inside the facts.

Iterate by copying the campaign and submitting a new guarded variant, not by editing live copy until the cell is unreadable. The assistant can draft the next line. The claim check decides whether it may run.

The same account can still launch from a prompt. Prompt to campaign objects is the object path. This page is the copy path. A prompt that creates a campaign with invented proof is two failures at once: a cell you cannot explain, and a banner the landing page cannot keep. Keep the draft. Drop the unsourced claim.