Merge pull request #272 from apollographql/GT-349

fix: generate openAI-compatible json schemas for list types

Author: DaleSeo

.changesets/fix_openai_incompatibility.md

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+### fix: generate openAI-compatible json schemas for list types - @DaleSeo PR #272
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+The MCP server is generating JSON schemas that don't match OpenAI's function calling specification. It puts `oneOf` at the array level instead of using `items` to define the JSON schemas for the GraphQL list types. While some other LLMs are more flexible about this, it technically violates the [JSON Schema specification](https://json-schema.org/understanding-json-schema/reference/array) that OpenAI strictly follows.
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+This PR updates the list type handling logic to move `oneOf` inside `items` for GraphQL list types.