feat: add canonical typed tool outputs

packages/ui/tool-ask-user/README.md

@@ -13,7 +13,7 @@ Model-facing `ask_user_question` tool over `ctx.userInteraction`. It lets the mo
 - `options` — optional choices with `label` and `description`. If recommending a choice, put it first and append `(Recommended)` to that label.
 - `multi_select` — whether that question may return more than one selected option.
 
-The tool calls `ctx.userInteraction.ask()` and returns JSON text shaped as `{ "answers": [{ "id": "...", "selected": ["..."], "custom": "..." }] }`. `selected` contains option labels; `custom` is present only for a free-form answer and overrides selected choices.
+The tool calls `ctx.userInteraction.ask()` and returns canonical `{ answers: [{ id, selected, custom? }] }`. `selected` contains option labels; `custom` is present only for a free-form answer and overrides selected choices. The Native renderer preserves the compact JSON text shape `{ "answers": [{ "id": "...", "selected": ["..."], "custom": "..." }] }`.
 
 ## Role
 
@@ -52,4 +52,4 @@ Append-only; newly visible content follows the reusable request prefix and does
 ## Known Limitations and Deferred Work
 
 - **A pending question blocks the tool call until the human answers** — the tool declares no `timeout-policy` budget; cancellation rides the turn's `exec.signal` only.
-- **Answers return as JSON text** — the seam's structured `AskUserQuestionAnswer` is serialized into the tool result rather than carried as typed content blocks.
+- **Native answers render as JSON text** — the canonical value remains structured, but the model-facing result uses compact JSON rather than a richer content-block vocabulary.

packages/ui/tool-ask-user/src/index.ts

@@ -55,6 +55,28 @@ export function apply(ctx: Context): void {
         },
       },
     },
+    output: {
+      schema: {
+        type: 'object',
+        additionalProperties: false,
+        properties: {
+          answers: {
+            type: 'array',
+            required: true,
+            items: {
+              type: 'object',
+              additionalProperties: false,
+              properties: {
+                id: { type: 'string', required: true },
+                selected: { type: 'array', required: true, items: { type: 'string' } },
+                custom: { type: 'string' },
+              },
+            },
+          },
+        },
+      },
+      render: (_args, value) => [{ type: 'text', text: JSON.stringify(value) }],
+    },
     async execute(args, exec) {
       const result = await ctx.userInteraction.ask({
         questions: args.questions.map(question => ({
@@ -67,7 +89,13 @@ export function apply(ctx: Context): void {
         ...exec.agent !== undefined ? { agent: exec.agent } : {},
         ...exec.signal !== undefined ? { signal: exec.signal } : {},
       })
-      return [{ type: 'text', text: JSON.stringify(result) }]
+      return {
+        answers: result.answers.map(answer => ({
+          id: answer.id,
+          selected: [...answer.selected],
+          ...answer.custom !== undefined ? { custom: answer.custom } : {},
+        })),
+      }
     },
   }))
 }

packages/ui/tool-ask-user/tests/tool-ask-user.spec.ts

@@ -159,6 +159,14 @@ describe('ask_user_question tool', () => {
       },
     })
 
+    expect(result.isError).toBe(false)
+    if (result.isError) throw new Error('expected ask_user_question success')
+    expect(result.value).toEqual({
+      answers: [
+        { id: 'targets', selected: ['tests', 'docs'] },
+        { id: 'notes', selected: [], custom: 'ship today' },
+      ],
+    })
     expect(result.content).toEqual([{
       type: 'text',
       text: '{"answers":[{"id":"targets","selected":["tests","docs"]},{"id":"notes","selected":[],"custom":"ship today"}]}',
@@ -219,7 +227,7 @@ describe('ask_user_question tool', () => {
 
     expect(result).toMatchObject({
       isError: true,
-      error: { name: 'UserInteractionError', code: 'NO_PROVIDER' },
+      error: { info: { name: 'UserInteractionError', code: 'NO_PROVIDER' } },
     })
   })
 
@@ -234,7 +242,7 @@ describe('ask_user_question tool', () => {
 
     expect(result).toMatchObject({
       isError: true,
-      error: { name: 'UserInteractionError', code: 'EMPTY_QUESTIONS' },
+      error: { info: { name: 'UserInteractionError', code: 'EMPTY_QUESTIONS' } },
     })
   })