fix(core): recover malformed tool input

packages/ai/src/protocols/shared.ts

@@ -153,7 +153,21 @@ export const wrappedSystemUpdate = Effect.fn("ProviderShared.wrappedSystemUpdate
  * routes: `Invalid JSON input for <route> tool call <name>`.
  */
 export const parseToolInput = (route: string, name: string, raw: string) =>
-  parseJson(route, raw || "{}", `Invalid JSON input for ${route} tool call ${name}`)
+  Effect.try({
+    try: () => decodeJson(raw || "{}"),
+    catch: () =>
+      new LLMError({
+        module: "ProviderShared",
+        method: "stream",
+        reason: new InvalidProviderOutputReason({
+          route,
+          message: `Invalid JSON input for ${route} tool call ${name}`,
+          raw,
+          source: "tool-input",
+          toolName: name,
+        }),
+      }),
+  })
 
 export const IMAGE_MIMES = ["image/png", "image/jpeg", "image/gif", "image/webp"] as const
 export const VIDEO_MIMES = ["video/mp4", "video/webm", "video/quicktime"] as const

packages/ai/src/schema/errors.ts

@@ -106,6 +106,8 @@ export class InvalidProviderOutputReason extends Schema.Class<InvalidProviderOut
   message: Schema.String,
   route: Schema.optional(Schema.String),
   raw: Schema.optional(Schema.String),
+  source: Schema.optional(Schema.Literal("tool-input")),
+  toolName: Schema.optional(Schema.String),
   providerMetadata: Schema.optional(ProviderMetadata),
 }) {}
 

packages/ai/test/tool-stream.test.ts

@@ -64,6 +64,25 @@ describe("ToolStream", () => {
     }),
   )
 
+  it.effect("classifies malformed tool input with its raw arguments", () =>
+    Effect.gen(function* () {
+      const tools = ToolStream.start(ToolStream.empty<number>(), 0, {
+        id: "call_1",
+        name: "lookup",
+        input: '{"query":"partial',
+      })
+      const error = yield* ToolStream.finish(ADAPTER, tools, 0).pipe(Effect.flip)
+
+      expect(error).toBeInstanceOf(LLMError)
+      expect(error.reason).toMatchObject({
+        _tag: "InvalidProviderOutput",
+        source: "tool-input",
+        toolName: "lookup",
+        raw: '{"query":"partial',
+      })
+    }),
+  )
+
   it.effect("preserves providerExecuted and clears all tools", () =>
     Effect.gen(function* () {
       const first: ToolStream.State<number> = ToolStream.start(ToolStream.empty<number>(), 0, {