fix agent responding with repeating content

[zanesq]

Noticed since streaming was added we're getting a lot of repeated "I found the issue!" type responses that loop over and over again repeating the same thing but with variations in the response text. The agent eventually recovers and continues but pretty sure it didn't do this before.

Here is an example:

From goose:

The Problem

The current version is missing the final output tool handling when there are no tool requests. This means:

Agent generates a response with no tool calls
Instead of checking if it should end or continue, it just continues the loop
This causes the agent to generate another response to the same input
This repeats, causing the "multiple similar responses" you're seeing

The Fix

The current version needs the final output tool handling logic from the original version.

The Root Cause

In the current version (line ~522), when there are no tool requests, the code simply does:

let num_tool_requests = frontend_requests.len() + remaining_requests.len();
if num_tool_requests == 0 {
    continue;  // This just continues the loop!
}

But in the original version, there's additional logic to handle the final_output_tool:

if num_tool_requests == 0 {
    if let Some(final_output_tool) = self.final_output_tool.lock().await.as_ref() {
        if final_output_tool.final_output.is_none() {
            // Continue the agent loop with a continuation message
            let message = Message::user().with_text(FINAL_OUTPUT_CONTINUATION_MESSAGE);
            messages.push(message.clone());
            yield AgentEvent::Message(message);
            continue;
        } else {
            // Return the final output and end
            let message = Message::assistant().with_text(final_output_tool.final_output.clone().unwrap());
            messages.push(message.clone());
            yield AgentEvent::Message(message);
            added_message = true;
            push_message(&mut messages, response);
            continue;
        }
    }
    continue;
}

What's Happening

The current version is missing the final output tool handling logic. This means:

The agent responds to "hi"
When there are no tool requests, it just continues the loop
The agent loop continues indefinitely, causing the agent to keep responding to the same context
Each time it responds, it generates a slightly different response (which explains why you see different content each time)

The Fix

I've added the missing logic from the original version. This should fix the repeated responses issue by properly handling the final output tool and breaking the loop when appropriate.

The key insight is that the agent was stuck in an infinite loop because it wasn't properly checking for completion conditions when there were no tool requests to process.

[jsibbison-square]

@zanesq can you tell me more about the scenario you are seeing this for? I fixed running recipes that had a final output tool when streaming that was causing bad behavior. Is that when not using recipes? It required removing the code you are adding #3448 so I would like to replicate the problem you are seeing. I added a test to simulate the original failure which is what is failing on your PR when you change the logic.

[zanesq]

@jsibbison-square I'm seeing the agent loop a lot now like the screenshot shows when not running recipes. I don't have any experience with the agent code so I asked goose to take a look at what changed and might be causing the issue. I'm running the branch locally now to see if it fixes the issue will report back. Also open to other ideas for this.

[jsibbison-square]

It sounds to me more like "normal" agent behavior of long or agent is confused sessions. I'm not 100% but if that section of code was preventing an agent from finishing I would expect all agent loops to never finish. But they are finishing and it only sometimes seems to loop. So I think its a more fundamental issue but please let us know what you discover in case I'm wrong. I'm running on main now and not hitting any unusual looping behavior. (I assume you are testing this with a streaming provider)

[jamadeo]

It looks like it's supposed to be calling a tool, but the tool call isn't there? The end of the prompt saying e.g. "Let me look at the current structure ... :"