[Bug] Gemini models reject edit tool due to anyOf schema violation in parameters.edits

[ArtanisInc]

Description

When using Gemini models (e.g. gemini-3-pro-preview, gemini-3.1-pro-preview) via the native google provider, all requests fail with:

Bad Request: Unable to submit request because `edit` functionDeclaration `parameters.edits` schema specified other fields alongside any_of. When using any_of, it must be the only field set.

The issue is that the edit tool's function declaration schema uses anyOf combined with other fields (like type, description, properties, etc.) in the parameters.edits property. This is valid JSON Schema but violates Google's API constraint that when anyOf is used, it must be the only field set in that schema object.

Plugins

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OpenCode version

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Steps to reproduce

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Screenshot and/or share link

• Related: [Bug]: google provider doesn't allow any requests pro 3 and 3.1 jenslys/opencode-gemini-auth#57

Operating System

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Terminal

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[github-actions]

This issue might be a duplicate of existing issues. Please check:

• Gemini: all requests fail due to anyOf schema in github_create_pull_request_review tool #14509: Same root cause — Gemini API rejects anyOf schemas that have sibling fields, causing all requests to fail. That issue covers the same fix needed in sanitizeGemini to strip sibling fields when anyOf is present.
• Gemini: sanitizeGemini doesn't handle anyOf/const patterns in MCP tool schemas #12908: Related — Gemini sanitizeGemini not handling anyOf/const patterns in MCP tool schemas.

If your issue is specifically about the built-in edit tool (rather than MCP tools), it may be a separate manifestation worth tracking, but please review those issues first and consider adding a comment there if they cover your scenario.