ToolResultContract

The tool-result contract (design §5.3 of the typed agent runtime): every tool call a request carries has exactly one result, straight after the message that made it, in the provider's own format - and no result answers a call that is not there. OpenAI rejects a request that breaks it; Anthropic rejects one too, which is why an Anthropic client must never be handed such a conversation, rather than drop or rewrite what does not pair.

violations reads a request body; cases are the conversations an agent's tool loop sends after every outcome of a call - success, a tool error, a rejection or denial, an unknown tool, a refused handoff batch, a handoff - including provider call ids reused across turns. ProviderModuleChecks.assertOneToolResultPerCall sends each case through a client and checks what reaches the server.