Zod Validation error when streaming MCP tool calls from Langgraph Agent

Hi Team,

I'm getting these Zod Validation errors when streaming tool calls via the @ag-ui/client & @ag-ui/core npm packages.

This specifically happens when the Langgraph Agent is leveraging tools of an MCP Server,

Attaching my npm packages - I believe they're all the latest

```
"@ag-ui/client": "^0.0.43",
"@ag-ui/langgraph": "^0.0.22",
"@copilotkit/react-core": "^1.50.1",
"@copilotkit/react-ui": "^1.50.1",
"@copilotkit/runtime": "^1.50.1",
"@copilotkit/runtime-client-gql": "^1.50.1",
"@copilotkit/shared": "^1.50.1",
"@copilotkitnext/agent": "^0.0.33",
"@copilotkitnext/core": "^0.0.33",
"@copilotkitnext/react": "^0.0.33",
"@copilotkitnext/runtime": "^0.0.33",
```

And my error that I see in the NextJS Frontend

```
Console ZodError

[
{
"code": "invalid_type",
"expected": "string",
"received": "undefined",
"path": [
"toolCallId"
],
"message": "Required"
},
{
"code": "invalid_type",
"expected": "string",
"received": "undefined",
"path": [
"content"
],
"message": "Required"
}
]

Call Stack
26

Hide 26 ignore-listed frame(s)
get error
node_modules/@ag-ui/core/node_modules/zod/v3/types.js (39:1)
ZodDiscriminatedUnion.parse
node_modules/@ag-ui/core/node_modules/zod/v3/types.js (114:1)
Object.next
node_modules/@ag-ui/client/dist/index.mjs (6:1180)
ConsumerObserver.next
../src/internal/Subscriber.ts (161:25)
Subscriber._next
../src/internal/Subscriber.ts (119:22)
Subscriber.next
../src/internal/Subscriber.ts (75:12)
eval
../src/internal/Subject.ts (68:20)
errorContext
../src/internal/util/errorContext.ts (29:5)
Subject.next
../src/internal/Subject.ts (61:17)
t
node_modules/@ag-ui/client/dist/index.mjs (6:20)
Object.next
node_modules/@ag-ui/client/dist/index.mjs (4:9158)
ConsumerObserver.next
../src/internal/Subscriber.ts (161:25)
Subscriber._next
../src/internal/Subscriber.ts (119:22)
Subscriber.next
../src/internal/Subscriber.ts (75:12)
eval
../src/internal/Subject.ts (68:20)
errorContext
../src/internal/util/errorContext.ts (29:5)
Subject.next
../src/internal/Subject.ts (61:17)
ReplaySubject.next
../src/internal/ReplaySubject.ts (65:15)
Object.next
node_modules/@ag-ui/client/dist/index.mjs (6:969)
ConsumerObserver.next
../src/internal/Subscriber.ts (161:25)
Subscriber._next
../src/internal/Subscriber.ts (119:22)
Subscriber.next
../src/internal/Subscriber.ts (75:12)
eval
../src/internal/operators/switchMap.ts (115:42)
OperatorSubscriber._this._next
../src/internal/operators/OperatorSubscriber.ts (70:13)
Subscriber.next
../src/internal/Subscriber.ts (75:12)
eval
node_modules/@ag-ui/client/dist/index.mjs (4:8724)
```