fix: disable strict mode for MCP tools to preserve optional parameters

MCP tools (like Linear's MCP server) have optional parameters that were broken
by OpenAI's strict mode which requires ALL properties to be in the required array.

This change:
- Checks if tool name starts with 'mcp--' prefix
- Sets strict: false for MCP tools
- Preserves original schema without forcing all properties to required

Fixes ROO-241

Author: daniel-lxs

src/api/providers/base-provider.ts

@@ -28,18 +28,26 @@ export abstract class BaseProvider implements ApiHandler {
 			return undefined
 		}
 
-		return tools.map((tool) =>
-			tool.type === "function"
-				? {
-						...tool,
-						function: {
-							...tool.function,
-							strict: true,
-							parameters: this.convertToolSchemaForOpenAI(tool.function.parameters),
-						},
-					}
-				: tool,
-		)
+		return tools.map((tool) => {
+			if (tool.type !== "function") {
+				return tool
+			}
+
+			// MCP tools use the 'mcp--' prefix - disable strict mode for them
+			// to preserve optional parameters from the MCP server schema
+			const isMcpTool = tool.function.name.startsWith("mcp--")
+
+			return {
+				...tool,
+				function: {
+					...tool.function,
+					strict: !isMcpTool,
+					parameters: isMcpTool
+						? tool.function.parameters
+						: this.convertToolSchemaForOpenAI(tool.function.parameters),
+				},
+			}
+		})
 	}
 
 	/**

src/api/providers/openai-native.ts

@@ -291,13 +291,20 @@ export class OpenAiNativeHandler extends BaseProvider implements SingleCompletio
 			...(metadata?.tools && {
 				tools: metadata.tools
 					.filter((tool) => tool.type === "function")
-					.map((tool) => ({
-						type: "function",
-						name: tool.function.name,
-						description: tool.function.description,
-						parameters: ensureAllRequired(tool.function.parameters),
-						strict: true,
-					})),
+					.map((tool) => {
+						// MCP tools use the 'mcp--' prefix - disable strict mode for them
+						// to preserve optional parameters from the MCP server schema
+						const isMcpTool = tool.function.name.startsWith("mcp--")
+						return {
+							type: "function",
+							name: tool.function.name,
+							description: tool.function.description,
+							parameters: isMcpTool
+								? tool.function.parameters
+								: ensureAllRequired(tool.function.parameters),
+							strict: !isMcpTool,
+						}
+					}),
 			}),
 			...(metadata?.tool_choice && { tool_choice: metadata.tool_choice }),
 		}