{
  "next_tool_name": "finish",
  "next_tool_args": {
    "type": "relative",
    "start_expression": "-1 week",
    "end_expression": "-1 week",
    "granularity": "week",
    "confidence": 0.95
  }
}

At runtime, DSPy validates finish against args={} and records an execution error similar to:

ValueError: Arg type is not in the tool's args.

However, ReAct still breaks out of the loop after finish and then runs the extraction step, so the final prediction can still be
correct.

This creates a misleading failure mode:

- the trajectory contains an execution error even though the run may succeed
- logs become noisy and look like a tool failure
- users are forced to add prompt workarounds such as "finish must always use {}"

From a framework perspective, this feels like an abstraction leak in ReAct, because users need to understand the internal split
between the tool loop and the later extraction pass to avoid this.

### Steps to reproduce


import dspy

class MySig(dspy.Signature):
    text: str = dspy.InputField()
    type: str = dspy.OutputField()
    start_expression: str = dspy.OutputField()
    end_expression: str = dspy.OutputField()
    granularity: str = dspy.OutputField()
    confidence: float = dspy.OutputField()

def ask_human_time(prompt: str) -> str:
    return "last week"

lm = dspy.LM("openai/gpt-4o-mini")  # replace with any model that tends to put final outputs into finish args
dspy.configure(lm=lm)

react = dspy.ReAct(MySig, tools=[ask_human_time], max_iters=3)
pred = react(text="What was the FPY for ADPRR at PTI?")

print(pred.trajectory)
print(pred)

Observed behavior:

1. the model may call ask_human_time
2. then it may call finish with structured output fields in next_tool_args
3. DSPy records an execution error for finish
4. the final extraction step may still return a valid prediction

### Expected behavior

One of the following should happen:

1. finish should accept structured final outputs, or
2. extra args passed to finish should be ignored instead of being treated as a tool execution error, or
3. ReAct should provide a clearer structured way to separate "end the tool loop" from "return final outputs"

At minimum, the current behavior should not produce a misleading execution error for a common model behavior.

### Additional context

There is a related open feature request about finish and the extraction step:
https://github.com/stanfordnlp/dspy/issues/8484

Also, the current main branch still defines finish as a no-arg tool in dspy/predict/react.py.

### DSPy version

3.0.4