Invalid Format: Missing 'Action:' after 'Thought

TL;DR

For "Error executing tool. Missing exact 3 pipe (|) separated values. For example, coworker|task|information.": issue crewAIInc/crewAI#103 (closed, 40 comments): My agent keep running into this error whenever I use any of the models locally (I tried llama2, openhermes, starling and Mistral). The only model that didn't run into this problem is Mistral.

Error executing tool. Missing exact 3 pipe (|) separated values. For example, `coworker|task|information`.

Steps

1. Issue crewAIInc/crewAI#103 (closed, 40 comments): My agent keep running into this error whenever I use any of the models locally (I tried llama2, openhermes, starling and Mistral). The only model that didn't run into this problem is Mistral. Very often this error is followed by another error: "Error executing tool. Missing exact 3 pipe (|) separated values. For example, coworker|task|information." Whenever any of these two errors appeared, I wouldn't be able to get any valid output. I was experimenting with simple examples like internet scraping with DuckDuckGo and custom reddit scraping tool. Also, worth mentioning, I don't have these prob
2. Reporters confirmed two workarounds for the ReAct parse failure with local models: (1) raise the model context window - Ollama defaults to 2048 tokens, and setting num_ctx=16384 fixed it (reporter kyuumeitai; yunusemreyavuzz: 'I solved the problem by increasing the context length'). (2) keep task prompts from reformatting CrewAI's internal keywords - kingychiu added 'These keywords must never be translated and transformed: Action:, Thought:, Action Input:' to task prompts, confirmed working by owaisafaq. Collaborator joaomdmoura noted small local models struggle with tool-calling cognition and closed the issue pending better docs on best models.

When to use

You are seeing this: Very often this error is followed by another error: "Error executing tool. Use this skill when you run into "Invalid Format: Missing 'Action:' after 'Thought".

When not to use

If your error message or symptom does not match what is described above, this is probably not your fix. Search for your exact error text instead of forcing this one to fit.

Versions

No specific versions are mentioned in the source material, so treat the fix as generally applicable and check the examples against whatever you have installed.

Why this happens

The original report does not dig into a root cause. It documents the symptom and the fix that resolved it.

Edge cases

• Also, worth mentioning, I don't have these prob

In gh:crewAIInc/crewAI#103 (https://github.com/crewAIInc/crewAI/issues/103), someone reported: Issue crewAIInc/crewAI#103 (closed, 40 comments): My agent keep running into this error whenever I use any of the models locally (I tried llama2, openhermes, starling and Mistral). The only model that didn't run into this problem is Mistral. Very often this error is followed by another error: "Error executing tool. Missing exact 3 pipe (|) separated values. For example, coworker|task|information." Whenever any of these two errors appeared, I wouldn't be able to get any valid output. I was experimenting with simple examples like internet scraping with DuckDuckGo and custom reddit scraping tool. Also, worth mentioning, I don't have these prob The verified resolution from the thread: Reporters confirmed two workarounds for the ReAct parse failure with local models: (1) raise the model context window - Ollama defaults to 2048 tokens, and setting num_ctx=16384 fixed it (reporter kyuumeitai; yunusemreyavuzz: 'I solved the problem by increasing the context length'). (2) keep task prompts from reformatting CrewAI's internal keywords - kingychiu added 'These keywords must never be translated and transformed: Action:, Thought:, Action Input:' to task prompts, confirmed working by owaisafaq. Collaborator joaomdmoura noted small local models struggle with tool-calling cognition and closed the issue pending better docs on best models.