Greptile Summary

This PR sanitizes tool parameter schemas before forwarding them to the Vertex/Gemini API, which rejects JSON Schema keywords it does not recognize. Both the chat-completions (convert_tools) and responses API (convert_responses_tools_to_vertex) paths are updated.

• Adds sanitized_parameters, which chains inline_schema_refs (resolves $ref/$defs into place) and retain_supported_keys (strips every keyword not in Gemini's closed Schema allowlist) before passing parameters to VertexFunctionDeclaration.
• Includes a fix for sibling schema-valued keywords (e.g. an anyOf co-located with a $ref) that themselves carry nested $ref values — each sibling is now passed through resolve_refs before being merged into the resolved target, preventing the allowlist pass from collapsing them to {}.
• Adds four tests in responses_api_tests and two in a new tool_conversion_tests module covering unsupported-key stripping, $ref/$defs inlining, recursive-ref degradation, property-name/enum-value preservation, and the sibling-$ref case.

Confidence Score: 5/5

Safe to merge — the change is purely additive sanitization applied before parameters reach the Vertex wire format, with no effect on any other code path.

The sanitization pipeline is logically correct: ref inlining runs before the allowlist strip, recursive schemas are detected via the active stack and degraded gracefully, and sibling schema-valued keywords are themselves passed through resolve_refs before being merged. Both changed call-sites are covered by the new tests, including the previously-flagged sibling-anyOf case. No existing behavior is altered for schemas that were already clean.

No files require special attention.

Important Files Changed

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    A["tool.function.parameters\n(Option<Value>)"] --> B["sanitized_parameters()"]
    B --> C{"is Some?"}
    C -- No --> Z["None → passed to Vertex"]
    C -- Yes --> D["inline_schema_refs()"]
    D --> D1["lift root $defs / definitions\ninto lookup table"]
    D1 --> D2["resolve_refs() — recursive"]
    D2 --> D3{"has $ref?"}
    D3 -- No --> D4["recurse into all child values"]
    D3 -- Yes --> D5{"name in active stack?"}
    D5 -- Yes/cycle --> D6["substitute {type: object}"]
    D5 -- No/found --> D7["clone target, push active,\nresolve_refs target, pop active"]
    D5 -- No/not found or non-local --> D6
    D7 --> D8["resolve each sibling via resolve_refs,\nor_insert into resolved target"]
    D8 --> D9["*value = replacement"]
    D6 --> D9
    D4 --> E["retain_supported_keys()"]
    D9 --> E
    E --> E1["map.retain — drop keys not in allowlist"]
    E1 --> E2["recurse into properties values"]
    E2 --> E3["recurse into items (object or array)"]
    E3 --> E4["recurse into anyOf variants"]
    E4 --> Z2["sanitized Value → passed to Vertex"]

_{Reviews (3): Last reviewed commit: "Review fixes" | Re-trigger Greptile}

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