# Some new MCP tools are breaking AI Models

**URL:** <https://community.fibery.io/t/some-new-mcp-tools-are-breaking-ai-models/10606>\
**Category:** Bugs & Issues\
**Tags:** mcp\
**Created:** [March 20, 2026, 10:04am UTC](https://community.fibery.io/t/some-new-mcp-tools-are-breaking-ai-models/10606 "2026-03-20T10:04:34Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![RonMakesSystems](https://sea2.discourse-cdn.com/flex020/user_avatar/community.fibery.io/ronmakessystems/32/14122_2.png) [@RonMakesSystems](https://community.fibery.io/u/RonMakesSystems)\
**Post date:** [March 20, 2026, 10:04am UTC](https://community.fibery.io/t/some-new-mcp-tools-are-breaking-ai-models/10606/1 "2026-03-20T10:04:34Z")

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Using some AI Models in n8n with the new MCP tools breaks it.

Gemini Error:  
Bad request - please check your parameters  
[GoogleGenerativeAI Error]: Error fetching from [https://generativelanguage.googleapis.com/v1beta/models/gemini-2.0-flash-lite:generateContent:](https://generativelanguage.googleapis.com/v1beta/models/gemini-2.0-flash-lite:generateContent:) [400 Bad Request] Invalid JSON payload received. Unknown name “type” at ‘tools[0].function\_declarations[47].parameters.properties[0].value.items.properties[3].value’: Proto field is not repeating, cannot start list. [{“@type”:“[type.googleapis.com/google.rpc.BadRequest",“fieldViolations”:[{“field”:“tools[0].function\_declarations[47].parameters.properties[0].value.items.properties[3].value”,“description”:"Invalid](http://type.googleapis.com/google.rpc.BadRequest%22,%22fieldViolations%22:%5B%7B%22field%22:%22tools%5B0%5D.function_declarations%5B47%5D.parameters.properties%5B0%5D.value.items.properties%5B3%5D.value%22,%22description%22:%22Invalid) JSON payload received. Unknown name "type" at ‘tools[0].function\_declarations[47].parameters.properties[0].value.items.properties[3].value’: Proto field is not repeating, cannot start list.”}]}]

Open AI Error:  
Bad request - please check your parameters

Invalid schema for function ‘query’: [{‘type’: ‘array’, ‘items’: {‘anyOf’: [{‘type’: ‘string’}, {‘type’: ‘array’, ‘items’: {‘type’: ‘string’}}]}, ‘minItems’: 1}, {‘type’: ‘string’, ‘enum’: [‘q/asc’, ‘q/desc’]}] is not of type ‘object’, ‘boolean’.

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<div class="post-metadata">

**Author:** ![RonMakesSystems](https://sea2.discourse-cdn.com/flex020/user_avatar/community.fibery.io/ronmakessystems/32/14122_2.png) [@RonMakesSystems](https://community.fibery.io/u/RonMakesSystems)\
**Post date:** [March 22, 2026, 12:59pm UTC](https://community.fibery.io/t/some-new-mcp-tools-are-breaking-ai-models/10606/2 "2026-03-22T12:59:15Z")

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Hey! Is this a bug or a problem with my implementation?

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**Author:** ![maxdubakov](https://sea2.discourse-cdn.com/flex020/user_avatar/community.fibery.io/maxdubakov/32/8347_2.png) [@maxdubakov](https://community.fibery.io/u/maxdubakov)\
**Post date:** [March 23, 2026, 9:30am UTC](https://community.fibery.io/t/some-new-mcp-tools-are-breaking-ai-models/10606/3 "2026-03-23T09:30:37Z")

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Hey! Most probably it was an incompatability on our side. OpenAI/Gemini do not allow `z.lazy` in zod schemas as well as recursive definitions. Deployed a fix, could you try now?