Why: a tool-budget stop left tool calls without results, host callbacks raced, a canceled MCP read stole the next response, and fetch re-resolved after the SSRF check. Evidence: GOWORK=off go vet ./... && go test -count=1 ./... && go test -race ./runtime/... ./adapters/native/... passed, including TestLoopBudgetToolCallCap, TestParallelHostCallbacksAreSerial, TestStdioSlowCancelThenEcho, TestPresetsAndClientForChatCompletions, TestFetchResolveChangesToLoopbackRejected, and TestFetchHostCheckRedirectStillRejectsPrivate. Impact: over-budget calls get an error result and no tool event; one Run serializes host callbacks; MCP dispatches by id; anthropic and google presets use OpenAI-compatible chat endpoints; fetch dials the address it just checked. deps/agent-intent is 3130190; error-code-system and logging-system are a3ee67b and 49b5d8b. Refs: N1, N2, N3, N4, N13, N14 Co-authored-by: Cursor <cursoragent@cursor.com>