[TGoodhew]

Fixes #164.

Problem

VS Code's Copilot (agent mode) refuses any tool whose schema has a "type": "array" without items:

Failed to validate tool mcp_gpib-mcp_gpib_batch: Error: tool parameters array type must have items.

gpib_batch's steps was a bare array, so the batch tool, which gpib_overview and BatchLoopNudge steer every sweep to, was missing in VS Code.

Changes

• steps now has an items schema: a step object with op (required, enum set | write | query | read | complete | wait), resource, command, value (number or string), unit, as, operation, settle_ms, timeout_ms. It keeps additionalProperties: true, so keys it doesn't know are still ignored. At runtime op is still matched without regard to case.
• sweep lists its properties: var, from, to, step, count, unit.
• ToolArgs gains ArrayOf(items, description) and ObjectOf(description, props...), plus Prop/Required overloads that take a schema. The plain Prop/Required(name, "array", ...) now throw, so an array can't be declared without its items again.
• instrument_reference's outputSchema: the new test found two more arrays without items, commandIndex and commands. They now have items too. (The issue thought only steps was affected.)

Tests

New ToolSchemaTests:

• walks every tool's inputSchema and outputSchema, at any depth, and asserts each array has items
• checks gpib_batch's step shape and op enum, and the sweep properties
• checks that the plain helpers refuse "array"

The full suite passes: 644 + 117. I also checked the schema the built server publishes in tools/list. Not yet tried in VS Code's Copilot itself.

Also fixes McpDispatcherTests.ToolsList_ReturnsAllToolsWithSchemas, which counted 32 tools rather than 31 on a PC with GPIB_MCP_MANUALS set, because manual_search is listed then. Because ManualSearchTests sets that variable while other classes run in parallel, the test could also fail in CI. The test now clears the variable for its own call and restores it, and it shares an xUnit collection with ManualSearchTests. Passes with the variable set and with it clear.

🤖 Generated with Claude Code

[Copilot]

🟡 Changes recommended

The regression test excludes view-only tools that are advertised to MCP Apps-capable clients.

1 open finding

• Schema regression check excludes advertised view-only tools · New

What changed in this PR

Adds complete JSON schemas so strict clients can load and use gpib_batch.

Changes:

• Defines batch step and sweep schemas.
• Adds reusable array/object schema helpers.
• Adds array-item validation tests and completes output schemas.

File	Description
ToolSchemaTests.cs	Tests schema completeness and batch shapes.
ToolArgs.cs	Adds structured schema helpers and array safeguards.
DatabaseTools.cs	Defines array item schemas for command output.
BatchTools.cs	Publishes detailed step and sweep schemas.

🧠 Review effort: Balanced

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