# clm_89B22687ECF8

subject: Anthropic (/record/anthropic.md)  
predicate: feature_added  
value: none option  
valid_from: 2025-02-27  
valid_to: null  
published: 2025-02-27  
recorded: 2026-11-14  
confidence: 0.70  
status: valid  
assertable: true  
superseded_by: null  
last_updated: 2026-11-14  
cite: AsOf. "Anthropic feature added: none option", as of 2025-02-27. Claim clm_89B22687ECF8, https://asof.is/claim/clm_89B22687ECF8, accessed 2026-11-14. Source: https://platform.claude.com/docs/en/release-notes/overview#2025-02-27.  
checked: 2026-11-14 · its source page states the value and the date, as read by an AI model  

> We’ve added support for a none option to the tool_choice parameter in the Messages API that prevents Claude from calling any tools.

What https://platform.claude.com/docs/en/release-notes/overview#2025-02-27 says, word for word.

## Sources

- https://platform.claude.com/docs/en/release-notes/overview#2025-02-27 (primary, Anthropic, published 2025-02-27)

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AsOf is a temporal fact ledger: a structured, dated, sourced record of what is true and what changed, built for AI retrieval.