AI: "Tool call not found" frequently occurs in recent versions

[askender]

Summary

Using the same API, this issue did not appear about 10 days ago, but in recent versions it now happens often.

Description

Steps to reproduce:

1. Start a chat
2. When the agent is about to solve the problem, it says: "Great! Now let me check the compilation errors in other files:"
3. Then it attempts to call a tool
4. Error occurs: Tool call not found

Expected Behavior:
The agent should successfully call and use the tool (tools are provided by Zed).

Actual Behavior:
Error is shown: Tool call not found

Model Provider Details

• Provider: Claude Sonnet 4 via API key (OpenAI-compatible).
  export OPENAI_BASE_URL OPENAI_API_KEY
• Model Name: claude-code-sonnet-4-20250514
• Mode: Agent Panel

It would be helpful if more detailed error information could be provided when this issue occurs.

---

Additionally, I have been a Zed Pro auto-renewal subscriber for 3 consecutive months, but suddenly my account was changed to a free user. This is strange since I have not modified any payment settings, and my payment method is working normally without any changes.

Zed Version and System Specs

Zed version: https://zed.dev/releases/stable/0.202.6
MacOS 15.5

[notpeter]

You said claude-code-sonnet-4-20250514, I assume you meant claude-sonnet-4-20250514?
Which provider are you actually using?

In general using Anthropic models via OpenAI API can have some issues as the provider/proxy/intermediary needs to adapt requests between the two APIs for everything to work properly. This is very much provider specific (e.g. OpenRouter does pretty well) and your experience will depend heavily on which of those corner cases are being adjusted for.

Additionally, I have been a Zed Pro auto-renewal subscriber for 3 consecutive months, but suddenly my account was changed to a free user. This is strange since I have not modified any payment settings, and my payment method is working normally without any changes.

That sounds super odd. Please contact [email protected] and include your github username so we can look into it.

[Bachstelze]

The frequent unknown tool calls also happen frequently with deepseek3.1 with inputs like:

  "content": "I need to check what's in the text_transformation directory to understand what LLM prompting functionality exists."
}```
Error: Missing tool call: The tool '' doesn't exist or is not enabled. 

[askender]

Seems it is solved by: #38207 : Create failed tool call entries for missing tools #38207

[israrwz]

still not solved.

i am only getting this error with claude sonnet 4.5 (though i use it through github copilot only).

Failed to connect to API: 400 Bad Request {"error":{"message":"messages.34.content.0: unexpected `tool_use_id` found in `tool_result` blocks: toolu_012fz4nFeDbv3qLtXFUhzHDu. Each `tool_result` block must have a corresponding `tool_use` block in the previous message.","code":"invalid_request_body"}}

some tool call is failing. and when i try to expand the tool call details, no information is shown on what tool was it. so there is no way to disable that specific tool call:

My environment:

Zed 0.206.6
f669540
MacOS Sequoia 15.0

[tulku]

Same error here:

Failed to connect to API: 400 Bad Request {"error":{"message":"messages.2.content.0: unexpected `tool_use_id` found in `tool_result` blocks: toolu_vrtx_01JRCMb7fdUEwuitjL4WrrBC. Each `tool_result` block must have a corresponding `tool_use` block in the previous message.","code":"invalid_request_body"}}

Also using Claude Sonnet 4.5 via Copilot.
Yesterday worked fine though.

[Kulimeya]

I'm using Sonnet 4.5 though Copilot and I also get this quite frequently.

Failed to connect to API: 400 Bad Request {"error":{"message":"messages.2.content.0: unexpected tool_use_idfound intool_resultblocks: toolu_vrtx_01AJwyYNg1UEBtxoRAEDZppC. Eachtool_resultblock must have a correspondingtool_useblock in the previous message.","code":"invalid_request_body"}}

[archbong]

I've been having this over the past few weeks, but today's error is just so annoying.

Failed to connect to DeepSeek API: 400 Bad Request {"error":{"message":"Messages with role 'tool' must be a response to a preceding message with 'tool_calls'","type":"invalid_request_error","param":null,"code":"invalid_request_error"}}

This error happens in multiple threads.
Please, what's the solution to this?

[vladiliescu]

Same here, getting the message below after 10-15 "tool call not found" messages. Using Sonnet 4.5 via Copilot. It seems to be triggered by planning things. The workaround is to use something like GPT-5 for planning, then switch to Sonnet 4.5 for the implementation. Issue doesn't happen when using Anthropic's Sonnet 4.5 directly.

So it's probably an issue with the Copilot model implementation.

Failed to connect to API: 400 Bad Request {"error":{"message":"messages.10.content.0: unexpected `tool_use_id` found in `tool_result` blocks: toolu_vrtx_014kjifJxQUZgQidPJxH8oNV. Each `tool_result` block must have a corresponding `tool_use` block in the previous message.","code":"invalid_request_body"}}

[Zjemm]

same issue here, also copilot. in vscode copilot still works fine, only in zed there is an issue

[patryk-ku]

For the past few days, I've been having the same issue with gemini-cli. It can't execute any shell commands and shows "Tool call not found". Previously, when it tried to run a command, it would ask for confirmation. I thought gemini-cli might be the problem, so I tried running it directly in the terminal, and the shell commands work just fine there.
ver: Zed 0.208.4

[igun997]

i got same issue too, recently got many frequent of tool call not found

[younux]

If you look at the ACP logs, you will see something like:

"I've assembled the parameters for the run_shell_command tool. "
"Command "XXXX" is not in the list of allowed tools for non-interactive mode."

This is an issue with gemini cli but it is not surfaced correctly in the Zed Agent panel .
To solve it, you need to allow the use of shell command in non interactive mode in ~/.gemini/settings.json

{
  "tools": {
    "allowed": [
      "run_shell_command"
    ]
  }
}

[patryk-ku]

Updated the config like you said, and it's working again. Thanks!