fix: use z.array(z.unknown()) to fix VS Code MCP schema validation error#27
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makafeli merged 2 commits intomakafeli:mainfrom Mar 19, 2026
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- VS Code >=1.99 validates MCP tool parameter schemas against JSON Schema spec. z.array(z.any()) produces {\"type\":\"array\"} without an 'items' field, which VS Code rejects with: 'tool parameters array type must have items'.
- Replacing with z.array(z.unknown()) produces {\"type\":\"array\",\"items\":{}} which satisfies VS Code's validator while keeping the same runtime behaviour.
- Affects: nodes and tags fields in create_workflow, update_workflow, and create_workflow_and_activate tool definitions.
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Problem
When using this MCP server with GitHub Copilot in VS Code (≥1.99), all tools that accept workflow objects fail to load with the error:
VS Code validates MCP tool parameter schemas against the JSON Schema spec, which requires array types to include an
itemsfield. The current code usesz.array(z.any()), which compiles to{"type": "array"}— missingitems.Fix
Change
z.array(z.any())→z.array(z.unknown())fornodesandtagsparameters.z.unknown()compiles to{}as the items schema, producing valid JSON Schema:{"type": "array", "items": {}}.Affected tools
create_workflowupdate_workflowcreate_workflow_and_activateImpact
z.unknown()accepts any value at runtime, same asz.any()tagIds,categories) already use typed schemas and are unaffectedTested
Verified with VS Code 1.111.0 + GitHub Copilot extension in Agent mode. After this fix, all 23 tools appear correctly and workflow CRUD operations work end-to-end.