feat(llm): pass strict through tool definitions for Codex parity (#33392)

packages/llm/src/protocols/openai-responses.ts

@@ -258,6 +258,8 @@ const lowerTool = (tool: ToolDefinition): OpenAIResponsesTool => ({
   name: tool.name,
   description: tool.description,
   parameters: ProviderShared.openAiToolInputSchema(tool.inputSchema),
+  // TODO: Read this from OpenAI-specific tool options so direct LLM callers can opt into strict schemas.
+  strict: false,
 })
 
 const lowerToolChoice = (toolChoice: NonNullable<LLMRequest["toolChoice"]>) =>

packages/llm/test/fixtures/recordings/openai-responses/gpt-5-5-drives-a-tool-loop.json

@@ -22,7 +22,7 @@
         "headers": {
           "content-type": "application/json"
         },
-        "body": "{\"model\":\"gpt-5.5\",\"input\":[{\"role\":\"system\",\"content\":\"Use the get_weather tool, then answer in one short sentence.\"},{\"role\":\"user\",\"content\":[{\"type\":\"input_text\",\"text\":\"What is the weather in Paris?\"}]}],\"tools\":[{\"type\":\"function\",\"name\":\"get_weather\",\"description\":\"Get current weather for a city.\",\"parameters\":{\"type\":\"object\",\"properties\":{\"city\":{\"type\":\"string\"}},\"required\":[\"city\"],\"additionalProperties\":false}}],\"stream\":true,\"max_output_tokens\":80}"
+        "body": "{\"model\":\"gpt-5.5\",\"input\":[{\"role\":\"system\",\"content\":\"Use the get_weather tool, then answer in one short sentence.\"},{\"role\":\"user\",\"content\":[{\"type\":\"input_text\",\"text\":\"What is the weather in Paris?\"}]}],\"tools\":[{\"type\":\"function\",\"name\":\"get_weather\",\"description\":\"Get current weather for a city.\",\"parameters\":{\"type\":\"object\",\"properties\":{\"city\":{\"type\":\"string\"}},\"required\":[\"city\"],\"additionalProperties\":false},\"strict\":false}],\"stream\":true,\"max_output_tokens\":80}"
       },
       "response": {
         "status": 200,
@@ -40,7 +40,7 @@
         "headers": {
           "content-type": "application/json"
         },
-        "body": "{\"model\":\"gpt-5.5\",\"input\":[{\"role\":\"system\",\"content\":\"Use the get_weather tool, then answer in one short sentence.\"},{\"role\":\"user\",\"content\":[{\"type\":\"input_text\",\"text\":\"What is the weather in Paris?\"}]},{\"type\":\"function_call\",\"call_id\":\"call_JCuVTkQxVB3cCmFWx52adJKZ\",\"name\":\"get_weather\",\"arguments\":\"{\\\"city\\\":\\\"Paris\\\"}\"},{\"type\":\"function_call_output\",\"call_id\":\"call_JCuVTkQxVB3cCmFWx52adJKZ\",\"output\":\"{\\\"temperature\\\":22,\\\"condition\\\":\\\"sunny\\\"}\"}],\"tools\":[{\"type\":\"function\",\"name\":\"get_weather\",\"description\":\"Get current weather for a city.\",\"parameters\":{\"type\":\"object\",\"properties\":{\"city\":{\"type\":\"string\"}},\"required\":[\"city\"],\"additionalProperties\":false}}],\"stream\":true,\"max_output_tokens\":80}"
+        "body": "{\"model\":\"gpt-5.5\",\"input\":[{\"role\":\"system\",\"content\":\"Use the get_weather tool, then answer in one short sentence.\"},{\"role\":\"user\",\"content\":[{\"type\":\"input_text\",\"text\":\"What is the weather in Paris?\"}]},{\"type\":\"function_call\",\"call_id\":\"call_JCuVTkQxVB3cCmFWx52adJKZ\",\"name\":\"get_weather\",\"arguments\":\"{\\\"city\\\":\\\"Paris\\\"}\"},{\"type\":\"function_call_output\",\"call_id\":\"call_JCuVTkQxVB3cCmFWx52adJKZ\",\"output\":\"{\\\"temperature\\\":22,\\\"condition\\\":\\\"sunny\\\"}\"}],\"tools\":[{\"type\":\"function\",\"name\":\"get_weather\",\"description\":\"Get current weather for a city.\",\"parameters\":{\"type\":\"object\",\"properties\":{\"city\":{\"type\":\"string\"}},\"required\":[\"city\"],\"additionalProperties\":false},\"strict\":false}],\"stream\":true,\"max_output_tokens\":80}"
       },
       "response": {
         "status": 200,

packages/llm/test/fixtures/recordings/openai-responses/gpt-5-5-streams-tool-call.json

@@ -14,7 +14,7 @@
         "headers": {
           "content-type": "application/json"
         },
-        "body": "{\"model\":\"gpt-5.5\",\"input\":[{\"role\":\"system\",\"content\":\"Call tools exactly as requested.\"},{\"role\":\"user\",\"content\":[{\"type\":\"input_text\",\"text\":\"Call get_weather with city exactly Paris.\"}]}],\"tools\":[{\"type\":\"function\",\"name\":\"get_weather\",\"description\":\"Get current weather for a city.\",\"parameters\":{\"type\":\"object\",\"properties\":{\"city\":{\"type\":\"string\"}},\"required\":[\"city\"],\"additionalProperties\":false}}],\"tool_choice\":{\"type\":\"function\",\"name\":\"get_weather\"},\"stream\":true,\"max_output_tokens\":80}"
+        "body": "{\"model\":\"gpt-5.5\",\"input\":[{\"role\":\"system\",\"content\":\"Call tools exactly as requested.\"},{\"role\":\"user\",\"content\":[{\"type\":\"input_text\",\"text\":\"Call get_weather with city exactly Paris.\"}]}],\"tools\":[{\"type\":\"function\",\"name\":\"get_weather\",\"description\":\"Get current weather for a city.\",\"parameters\":{\"type\":\"object\",\"properties\":{\"city\":{\"type\":\"string\"}},\"required\":[\"city\"],\"additionalProperties\":false},\"strict\":false}],\"tool_choice\":{\"type\":\"function\",\"name\":\"get_weather\"},\"stream\":true,\"max_output_tokens\":80}"
       },
       "response": {
         "status": 200,

packages/llm/test/provider/openai-responses.test.ts

@@ -115,6 +115,7 @@ describe("OpenAI Responses route", () => {
           type: "function",
           name: "read",
           description: "Read a path or resource.",
+          strict: false,
           parameters: {
             type: "object",
             properties: {

packages/opencode/src/session/llm/request.ts

@@ -146,6 +146,16 @@ export const prepare = Effect.fn("LLMRequestPrep.prepare")(function* (input: Pre
   )
 
   const tools = resolveTools(input)
+  // Codex parity: OpenAI Responses-family providers hardcode `strict: false`
+  // on every function tool so MCP-sourced and dynamic schemas that don't
+  // satisfy OpenAI's structured-outputs constraints still register.
+  if (
+    input.model.api.npm === "@ai-sdk/openai" ||
+    input.model.api.npm === "@ai-sdk/azure" ||
+    input.model.api.npm === "@ai-sdk/amazon-bedrock/mantle"
+  ) {
+    for (const key of Object.keys(tools)) tools[key] = { ...tools[key], strict: false }
+  }
   if (
     input.model.providerID.includes("github-copilot") &&
     Object.keys(tools).length === 0 &&

packages/opencode/test/provider/transform.test.ts

@@ -4,6 +4,7 @@ import { ProviderTransform } from "@/provider/transform"
 import { LLMRequestPrep } from "@/session/llm/request"
 import { ProviderV2 } from "@opencode-ai/core/provider"
 import { ModelV2 } from "@opencode-ai/core/model"
+import { jsonSchema } from "ai"
 
 describe("ProviderTransform.options - setCacheKey", () => {
   const sessionID = "test-session-123"
@@ -384,7 +385,12 @@ describe("ProviderTransform.options - gpt-5 textVerbosity", () => {
         } as any,
         system: [],
         messages: [{ role: "user", content: "Hello" }],
-        tools: {},
+        tools: {
+          lookup: {
+            description: "Look up a value",
+            inputSchema: jsonSchema({ type: "object", properties: {} }),
+          },
+        },
         provider: { id: "azure", options: { useCompletionUrls: true } } as any,
         auth: undefined,
         plugin: {
@@ -399,6 +405,7 @@ describe("ProviderTransform.options - gpt-5 textVerbosity", () => {
     expect(result.params.options.reasoningEffort).toBe("high")
     expect(result.params.options.reasoningSummary).toBeUndefined()
     expect(result.params.options.include).toBeUndefined()
+    expect(result.tools.lookup.strict).toBe(false)
   })
 
   test("gpt-5.1 should have textVerbosity set to low", () => {

packages/opencode/test/session/llm.test.ts

@@ -1314,6 +1314,7 @@ describe("session.llm.stream", () => {
             type: "function",
             name: "lookup",
             description: "Lookup data",
+            strict: false,
             parameters: {
               type: "object",
               properties: { query: { type: "string" } },
@@ -1402,6 +1403,7 @@ describe("session.llm.stream", () => {
             type: "function",
             name: "lookup",
             description: "Lookup data",
+            strict: false,
             parameters: {
               type: "object",
               properties: { query: { type: "string" } },