fix(translate): bail to non-strict for bare-{} optional tool args

[Symbiomancer]

Problem

Claude Code sessions routed to an OpenAI Responses-path model (gpt-5.x) were dying on the first turn that carried the Workflow tool:

API Error: 400 Invalid schema for function 'Workflow':
In context=('properties','args','anyOf','0','type','3'),
'additionalProperties' is required to be supplied and to be false.

Workflow.args is a bare {} "any JSON value" optional parameter. #829 addressed an earlier form of this 400 by having makeNullable synthesize a six-type union branch (["string","number","boolean","object","array","null"]) so the tool could stay strict:true. But that union admits "object", and OpenAI strict mode then requires the node to also carry additionalProperties:false — which the synthetic branch lacks. So the request still 400s, just one level deeper (note the error path lands on anyOf.0.type.3, i.e. index 3 = "object" of the synthesized union).

Why not just add additionalProperties:false to the synthetic branch?

Because a bare {} has no valid strict representation:

• Closing it with additionalProperties:false and no properties constrains args to an empty object only — breaking a parameter whose entire purpose is passing arbitrary JSON.
• Narrowing the type union to exclude object/array silently drops valid structured args.

An open value is exactly the case strictify is meant to bail on and fall back to non-strict emission (the file's documented fail-open contract). Non-strict emission is already the path for oneOf, unresolved $ref, tuple items, etc., and toolcheck still validates tool calls against the original schema downstream.

Change

• strictifyNode: when an optional property has no strict-expressible type (!schemaHasStrictType), return ok=false so the whole tool emits non-strict, instead of letting makeNullable synthesize an unrepresentable branch.
• makeNullable: revert the fix(translate): bail strict-mode strictification for typeless optional properties #829 typeless fallback back to wrapping the node in anyOf + null. That path is now unreachable behind the new guard; the comment says so.
• Replace TestStrictify_TypelessOptionalGetsExplicitValueType (asserted the now-wrong "stays strict" contract) with TestStrictify_TypelessOptionalBails.

Validation

• go vet ./internal/translate/ — clean
• go test ./internal/translate/... — pass (translate + toolcheck)
• wv mr tc — clean
• wv mr t (full router suite) — pass

🤖 Generated with Claude Code

[claude]

Claude finished @Symbiomancer's task —— View job

---

Advisory comment-length review posted on the PR diff.

[workweave-bot]

Advisory only — comment-length nits. Won't block merge.

[workweave-bot]

Suggested change

	// An optional property with no strict-expressible type (a bare {}
	// "any JSON value", e.g. Workflow.args) cannot be made nullable
	// without either admitting "object" — which strict mode then
	// requires to carry additionalProperties:false, forbidding the
	// arbitrary keys the schema exists to accept — or narrowing the
	// value space and silently dropping valid object/array args.
	// There is no strict representation of an open value, so bail to
	// non-strict emission per this file's fail-open contract.
	// A bare {} optional (open value) has no valid strict form: admitting
	// "object" requires additionalProperties:false (forbidding arbitrary keys),
	// and narrowing to non-object types drops valid structured args. Bail.

8 lines explaining a 2-step constraint; the WHY fits in 3.

[workweave-bot]

Suggested change

	// No type and no anyOf (e.g. bare enum): wrap the node itself. Callers must
	// not pass a fully typeless node here — strictifyNode bails on typeless
	// optionals before reaching this point, since an open value has no strict
	// representation (see the schemaHasStrictType guard in strictifyNode).
	// No type and no anyOf (e.g. bare enum): wrap node. Typeless optionals
	// are rejected by strictifyNode before reaching here.

4 lines; the caller-contract note and cross-reference both fit in 2.

[workweave-bot]

Suggested change

	// Workflow.args is a bare {} "any JSON value" optional. #829 kept it strict by
	// synthesizing a 6-type union branch, but that branch admits "object" without
	// additionalProperties:false, so OpenAI strict mode still 400'd
	// (context=('properties','args','anyOf','0','type','3')). An open value has no
	// strict representation, so the whole tool must bail to non-strict emission.
	// Workflow.args is a bare {} optional; an open value has no strict form
	// (#829's 6-type union still 400'd because "object" needs additionalProperties:false).

5 lines; the key WHY fits in 2.

[greptile-apps]

T-Rex Logs

What T-Rex did

• Ran go vet on internal/translate to validate static analysis, and it completed successfully within the 180-second timeout (exit code 0).
• Executed go test for internal/translate; both translate packages passed, with exit code 0 under the 180-second timeout.
• Ran the strictify-focused test for the translate package; TestStrictify completed with exit code 0.

_{Ran code and verified through T-Rex}

_{Reviews (1): Last reviewed commit: "fix(translate): bail to non-strict for b..." | Re-trigger Greptile}