fix: add strict mode support for OpenAI tool definitions in prompt-2025 endpoint

Users were receiving a 422 Unprocessable Entity error when creating prompts
with tool definitions that include OpenAI's strict mode (strict: true) and
additionalProperties: false in the function parameters.

Changes:
- Add `strict` field to OpenAIChatRequest tools function interface
- Make `description` and `parameters` optional in tool function definition
  to match OpenAI's API behavior
- Update internal Tool type to include `strict` property
- Update toExternalTools and convertTools functions to preserve the strict field
- Update TSOA validation schemas in routes.ts to accept strict mode

This allows prompts with tool calls using OpenAI's strict mode for function
calling to be created and validated correctly.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Co-Authored-By: Hammad Shami <hammad@helicone.ai>

Author: 3 people

packages/llm-mapper/mappers/openai/chat-v2.ts

@@ -37,8 +37,9 @@ export interface OpenAIChatRequest {
     type: "function";
     function: {
       name: string;
-      description: string;
-      parameters: Record<string, any>; // JSON Schema
+      description?: string;
+      parameters?: Record<string, any>; // JSON Schema
+      strict?: boolean;
     };
   }[];
   tool_choice?:
@@ -294,7 +295,8 @@ const toExternalTools = (
     function: {
       name: tool.name,
       description: tool.description,
-      parameters: tool.parameters || {},
+      parameters: tool.parameters,
+      strict: tool.strict,
     },
   }));
 };
@@ -311,6 +313,7 @@ const convertTools = (
     name: tool.function?.name,
     description: tool.function?.description,
     parameters: tool.function?.parameters,
+    strict: tool.function?.strict,
   }));
 };
 

packages/llm-mapper/types.ts

@@ -225,8 +225,9 @@ export type Response = {
 /* -------------------------------------------------------------------------- */
 export interface Tool {
   name: string;
-  description: string;
+  description?: string;
   parameters?: Record<string, any>; // Strict JSON Schema type ("parameters" in OPENAI, "input_schema" in ANTHROPIC)
+  strict?: boolean; // OpenAI's strict mode for function calling
 }
 export interface FunctionCall {
   id?: string;

valhalla/jawn/src/tsoa-build/private/routes.ts

@@ -931,7 +931,7 @@ const models: TsoaRoute.Models = {
             "max_completion_tokens": {"dataType":"double"},
             "stream": {"dataType":"boolean"},
             "stop": {"dataType":"union","subSchemas":[{"dataType":"array","array":{"dataType":"string"}},{"dataType":"string"}]},
-            "tools": {"dataType":"array","array":{"dataType":"nestedObjectLiteral","nestedProperties":{"function":{"dataType":"nestedObjectLiteral","nestedProperties":{"parameters":{"ref":"Record_string.any_","required":true},"description":{"dataType":"string","required":true},"name":{"dataType":"string","required":true}},"required":true},"type":{"dataType":"enum","enums":["function"],"required":true}}}},
+            "tools": {"dataType":"array","array":{"dataType":"nestedObjectLiteral","nestedProperties":{"function":{"dataType":"nestedObjectLiteral","nestedProperties":{"strict":{"dataType":"boolean"},"parameters":{"ref":"Record_string.any_"},"description":{"dataType":"string"},"name":{"dataType":"string","required":true}},"required":true},"type":{"dataType":"enum","enums":["function"],"required":true}}}},
             "tool_choice": {"dataType":"union","subSchemas":[{"dataType":"enum","enums":["none"]},{"dataType":"enum","enums":["auto"]},{"dataType":"enum","enums":["required"]},{"dataType":"nestedObjectLiteral","nestedProperties":{"function":{"dataType":"nestedObjectLiteral","nestedProperties":{"name":{"dataType":"string","required":true},"type":{"dataType":"enum","enums":["function"],"required":true}}},"type":{"dataType":"string","required":true}}}]},
             "parallel_tool_calls": {"dataType":"boolean"},
             "reasoning_effort": {"dataType":"union","subSchemas":[{"dataType":"enum","enums":["minimal"]},{"dataType":"enum","enums":["low"]},{"dataType":"enum","enums":["medium"]},{"dataType":"enum","enums":["high"]}]},

valhalla/jawn/src/tsoa-build/public/routes.ts

@@ -496,7 +496,7 @@ const models: TsoaRoute.Models = {
             "max_completion_tokens": {"dataType":"double"},
             "stream": {"dataType":"boolean"},
             "stop": {"dataType":"union","subSchemas":[{"dataType":"array","array":{"dataType":"string"}},{"dataType":"string"}]},
-            "tools": {"dataType":"array","array":{"dataType":"nestedObjectLiteral","nestedProperties":{"function":{"dataType":"nestedObjectLiteral","nestedProperties":{"parameters":{"ref":"Record_string.any_","required":true},"description":{"dataType":"string","required":true},"name":{"dataType":"string","required":true}},"required":true},"type":{"dataType":"enum","enums":["function"],"required":true}}}},
+            "tools": {"dataType":"array","array":{"dataType":"nestedObjectLiteral","nestedProperties":{"function":{"dataType":"nestedObjectLiteral","nestedProperties":{"strict":{"dataType":"boolean"},"parameters":{"ref":"Record_string.any_"},"description":{"dataType":"string"},"name":{"dataType":"string","required":true}},"required":true},"type":{"dataType":"enum","enums":["function"],"required":true}}}},
             "tool_choice": {"dataType":"union","subSchemas":[{"dataType":"enum","enums":["none"]},{"dataType":"enum","enums":["auto"]},{"dataType":"enum","enums":["required"]},{"dataType":"nestedObjectLiteral","nestedProperties":{"function":{"dataType":"nestedObjectLiteral","nestedProperties":{"name":{"dataType":"string","required":true},"type":{"dataType":"enum","enums":["function"],"required":true}}},"type":{"dataType":"string","required":true}}}]},
             "parallel_tool_calls": {"dataType":"boolean"},
             "reasoning_effort": {"dataType":"union","subSchemas":[{"dataType":"enum","enums":["minimal"]},{"dataType":"enum","enums":["low"]},{"dataType":"enum","enums":["medium"]},{"dataType":"enum","enums":["high"]}]},