Merge pull request #657 from apollographql/AMS-417

Gate outputSchema and structuredContent on negotiated MCP protocol version

Author: DaleSeo

.changeset/gate_output_schema_on_protocol_version.md

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+# Gate outputSchema and structuredContent on negotiated MCP protocol version
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+When `enable_output_schema` is configured, the server now advertises MCP protocol version `2025-06-18` and only includes `outputSchema` in `tools/list` and `structuredContent` in `tools/call` responses when the client negotiates a protocol version that supports them (`>= 2025-06-18`). Previously, these fields were sent regardless of the negotiated version, which could cause errors in clients that don't recognize them.