Tool not found: Task

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1

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

I receive an error, “Tool not found: Task”, when attempting to invoke any subagents. This happens when I use the Auto, Sonnet 4.5, and Opus 4.6 models, at least.

I have several sub agents defined in .cursor/agents (both inside the project and in my user directory). If I invoke any of them, the invocation fails, and the “default agent” takes over. The subagent appears in my slash command list, and appropriately turns into a tile within the chat (instead of text) when selected, but it will not invoke after submitting the chat message.

I ask each model to explain why they cannot invoke the subagent, and all responses are essentially the same. They all tell me that the Task tool is unavailable, which is consistent with the error message.

I did some debugging and found that the sub agent would actually active after turning on Share Data mode (instead of my default privacy mode), but I am starting to think that may have been coincidence, because I can no longer reproduce this.

Steps to Reproduce

  1. Be in Agent mode. Be in Privacy Mode (though not confirmed as related).

RAW PROBLEM:

  1. Declare a subagent in either (or both) the project-level .cursor/agents directory or the user-level one. Make sure the agent is instructed to do something very specific that is not related to the input you send it, like “always create a file called fred.md in the project root, containing the text ‘hello fred’ inside”.

  2. Attempt to use the subagent.

  3. Notice the task was completed as you described in the input, except your special instructions inside the agent were not followed (writing the fred.md file).

DEBUGGING PROBLEM:

  1. Tell the default chat agent to attempt to invoke your subagent with a simple task, and to record the output. Tell it to report any errors reported.

  2. Observe the agent responds by indicating the Task tool could not be found.

ALTERNATIVE DEBUGGING METHOD:

  1. Tell the chat agent to display an exhaustive list of all the tools available for use.

  2. Observe that the “Task” tool is not present

Expected Behavior

I expect the Task tool to be available for use, since it is required for subagent delegation. I expect that I can invoke a subagent, and it will work.

Operating System

MacOS

Version Information

Version: 2.4.37
VSCode Version: 1.105.1
Commit: 7b9c34466f5c119e93c3e654bb80fe9306b6cc70
Date: 2026-02-12T23:15:35.107Z
Build Type: Stable
Release Track: Default
Electron: 39.2.7
Chromium: 142.0.7444.235
Node.js: 22.21.1
V8: 14.2.231.21-electron.0
OS: Darwin arm64 24.6.0

For AI issues: which model did you use?

I tried:

  • Auto
  • Composer 1.0
  • Sonnet 4.5
  • Opus 4.6

All of these models showed the same issue

For AI issues: add Request ID with privacy disabled

Request ID: f1bff199-708a-4ad4-a93b-31428baabacb
Second Request ID (exploring correctness, per documentation): da657f16-14cd-42a2-82eb-49a51f8fd48e

Additional Information

I am trying to be more effective and speedy with my usage. It seems like subagents could really make a huge difference in my workflows, at a fundamental level. This feature would be a game changer if I can get it to work.

Also, I can use Cursor using my normal workflows, but since subagents are considered an available feature for the Pro+ plan, I feel like I am unable to use Cursor to its fullest capabilities right now.

Does this stop you from using Cursor

Yes - Cursor is unusable

3

Its unavailable for me too since upgrading to 2.4.37 while it worked before.

4

Hey, thanks for the detailed report.

For Auto and Composer 1, this is a known limitation. Composer 1 doesn’t support the Task tool, and Auto often gets routed to Composer 1 under the hood. That’s why subagents don’t work there.

But you’re saying Sonnet 4.5 and Opus 4.6 also fail, and that matters. Can you double check this. When you tested them, did you pick the model directly from the dropdown, not “Auto”? Auto can still route the request to Composer 1 even if you expected a different model.

To help the team debug this, we need a Request ID with Privacy Mode temporarily turned off.

  • Cursor Settings > Privacy Mode > switch to “Share Data”
  • Select Sonnet 4.5 (or Opus 4.6) directly from the model dropdown
  • Try calling the subagent in a new chat
  • Copy the Request ID (three dots in the chat > Copy Request ID)
  • Share it here, then turn Privacy Mode back on

The two Request IDs you shared were generated with Privacy Mode enabled, so our logs are limited.

Related threads for context:

@KwIg, same ask if possible. Did this work on a specific model before version 2.4.37, or in Auto mode?

5

Just tried again and today everything works again. Im using GPT 5.3 Codex and i also tried to call it yesterday in multiple new chats. I can’t share Request IDs though, since yesterday privacy mode was on, so I guess this is not of much help :woman_shrugging:

6

Hey Dean,

Thanks for the response.

Yesterday, I specifically tested this with the models you described, because I saw in older forum posts that Auto won’t work. The Request IDs in this report are specifically using one of those models. That is what led to submitting this bug report.

I also went through the email support, chatting with Sam the support bot, who eventually escalated this issue to the support team. In that chat, I included several additional request IDs.

With this in mind, something has definitely changed today, and not on my end, because it is working today. All of my subagents seem to work again now.

Thanks. This currently seems resolved.

Chris

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