fix(mcp): validate list tool SDK sidecars

[dodeja]

Summary

• declare the SDK unsupportedFilters sidecar in the list_containers and list_shipments MCP output schemas
• add end-to-end MCP client regression coverage using realistic mapped items / links / meta payloads
• verify response contracts and assistant-only steering content remain present

Root cause

The mapped SDK responses for both list managers always include a top-level unsupportedFilters array—even when empty. Their strict MCP output schemas omitted that property, so the MCP SDK rejected otherwise valid structured content with -32602 before returning it to schema-validating clients. list_tracking_requests uses a different SDK manager that does not add this sidecar, explaining why it remained valid.

Scope

Pagination and filter forwarding are unchanged. Arbitrary mapped item fields remain accepted by the existing record schema. Tool annotations remain read-only for all reads and non-read-only only for track_container. No reviewer fixtures or demo data are changed.

Verification

• npm run test --workspace @terminal49/mcp -- --run — 14 files, 184 tests passed
• npm run build --workspace @terminal49/mcp — passed
• npm run lint --workspace @terminal49/mcp — passed
• npx tsc --noEmit -p tsconfig.json — passed

The regression test calls both tools over a modern MCP client/HTTP transport, which exercises the SDK's actual output-schema validation path and covers mapped item fields, pagination links/meta, unsupportedFilters, _response_contract, and assistant-only _agent_steering content.

  

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Greptile Summary

This PR aligns the strict MCP output schemas for list_containers and list_shipments with the mapped SDK response shape and adds end-to-end regression coverage.

• Declares the top-level unsupportedFilters sidecar for both list tools.
• Tests empty and populated sidecars through a modern MCP client and HTTP transport.
• Verifies structured response contracts and assistant-only steering content remain available.

Confidence Score: 5/5

The PR appears safe to merge with no actionable correctness, security, or quality issues identified.

The schema additions match the documented mapped SDK response shape, preserve existing list behavior, and are covered through the actual MCP client and HTTP handler path for both affected tools.

Important Files Changed

Filename	Overview
packages/mcp/src/server.ts	Adds the SDK-provided unsupportedFilters array to both affected strict list-tool output schemas, resolving rejection of otherwise valid mapped responses.
packages/mcp/src/mcp.test.ts	Adds realistic client-level regression tests for both list tools, including mapped payloads, pagination metadata, response contracts, and assistant-only steering.

_{Reviews (1): Last reviewed commit: "fix(mcp): validate list tool sidecars" | Re-trigger Greptile}

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Project	Deployment	Actions	Updated (UTC)
api	Ready	Preview	Aug 21, 2026 6:02am

[vorflux]

Summary

Reviewed the changes to validate MCP list-tool SDK sidecars, including the output-schema handling and its integration with the existing tool response flow. The reviewed patch at 2a1166b71df8391b8482fd3c2d6544be84fc1602 did not reveal any actionable correctness, security, compatibility, error-handling, data-loss, or concurrency issues.

Verdict

✅ Reviewed — no issues found. The validation change is focused and consistent with the surrounding MCP tool behavior.