Agent response  undefined is not an object (evaluating '$.speed')

# Summary
We are utilizing the claude-agent-sdk (v0.1.56) for our coding agent. some users have reported a recurring error in the execution logs:
`Agent response: undefined is not an object (evaluating '$.speed')`

Environment:
```
claude-agent-sdk==0.1.56
anthropic>=0.40.0
```

Related:
https://github.com/anthropics/claude-code/issues/40737
https://github.com/anthropics/claude-code/issues/40189