fix: name run_code's required description argument in its model-facing prose

The transport schema requires both `code` and `description`, but the tool
description and both SDK instruction flavors described the call as passing a
program. `description` was reachable only through the parameter schema, so a
model following the prose emitted `{code}` alone and lost the whole written
program to an INVALID_ARGS rejection.

The length and format guidance stays in RUN_CODE_DESCRIPTION_PARAM_DESCRIPTION
alone, so the schema and the prompt cannot drift.

Fixes #2426

.agents/notes/implemented/feature/2026-06-15-code-mode.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write .agents/notes/implemented/feature/2026-06-15-code-mode.md
-2026-06-15-code-mode.md: f9bde7a85d9cf26d3d6670744c955380fa807e3b
-2026-06-15-code-mode.zh.md: 84fc5da63d6049e3533f753cf495aad37b075479
+2026-06-15-code-mode.md: 343ad4cf8191542016b492d6a16cdbf6c26b385c
+2026-06-15-code-mode.zh.md: 668def6cf7e74288c3e16253c4ebefb4781db633

.agents/notes/implemented/feature/2026-06-15-code-mode.md

@@ -87,6 +87,8 @@ The worker runtime provides containment, not a security boundary: model code can
 
 The SDK instructs the model to write an async body in the loaded runtime's language (an erasable-TypeScript body by default; a Python `async` body under a Python runtime — see the [language-dispatch note](2026-07-31-code-mode-language-dispatch.md)), call tools through `await tools.name(args)`, catch rejected tool calls when needed, and return or log only the output that should re-enter context. Both flavors state the same contract in their own primitive: independent read-only calls MAY overlap under `Promise.all` (TypeScript) or `asyncio.gather` (Python), mutating calls run alone in submission order, and dependent work sequences with `await`. The declaration prefix can be as large as native schemas, especially in `'both'`, but remains stable for provider caching.
 
+The transport's own `description` and both SDK instruction flavors open by naming `code` and `description` as the call's two required arguments. Prose that describes the call as passing a program leaves the second argument discoverable only through the parameter schema, and a model that emits `{code}` alone loses the whole written program to an `INVALID_ARGS` rejection.
+
 ## Consequences
 
 Deployments switching to `'code'` must update any native-only `toolOrder`. Assembly listeners own the integrity of any rewritten protocol messages. Sub-dispatch starts in submission order under a bounded overlap pool, while per-call contexts retain their source, envelope, and metadata through the outer result.

.agents/notes/implemented/feature/2026-06-15-code-mode.zh.md

@@ -87,6 +87,8 @@ worker 运行时只能约束程序的运行，而不构成安全边界：模型
 
 SDK 指示模型编写一个所加载运行时语言的异步函数体（默认可擦除 TypeScript；Python 运行时下为 Python `async` 函数体——见[语言分发 note](2026-07-31-code-mode-language-dispatch.md)），通过 `await tools.name(args)` 调用工具，在需要时捕获被拒绝的工具调用，并仅 return 或 log 应重新进入上下文的输出。两种 flavor 用各自的原语陈述同一约定：相互独立的只读调用可以（MAY）在 `Promise.all`（TypeScript）或 `asyncio.gather`（Python）下重叠，有副作用的调用按提交顺序单独运行，有依赖的工作用 `await` 排序。声明前缀可能与原生 schema 一样大，尤其在 `'both'` 下，但对提供方缓存保持稳定。
 
+传输自身的 `description` 与两种 flavor 的 SDK 说明都以点名 `code` 和 `description` 这两个必填参数开头。把该调用描述成「传入一个程序」的散文会让第二个参数只能从参数 schema 中发现，而只发出 `{code}` 的模型会因 `INVALID_ARGS` 被拒，连同已写好的整个程序一起丢失。
+
 ## 后果
 
 切换到 `'code'` 的部署必须更新任何仅限 native 的 `toolOrder`。组装监听器有责任维护任何被重写的协议消息的完整性。子分发在有界的重叠池下按提交顺序启动，而每次调用的上下文会通过外层结果保留其 source、信封与元数据。