Function isToolAllowedForMode

src/core/tools/validateToolUse.ts:120–239

(
	tool: string,
	modeSlug: string,
	customModes: ModeConfig[],
	toolRequirements?: Record<string, boolean>,
	toolParams?: Record<string, any>, // All tool parameters
	experiments?: Record<string, boolean>,
	includedTools?: string[], // Opt-in tools explicitly included (e.g., from modelInfo)
)

}

export function isToolAllowedForMode(
	tool: string,
	modeSlug: string,
	customModes: ModeConfig[],
	toolRequirements?: Record<string, boolean>,
	toolParams?: Record<string, any>, // All tool parameters
	experiments?: Record<string, boolean>,
	includedTools?: string[], // Opt-in tools explicitly included (e.g., from modelInfo)
): boolean {
	// Resolve alias to canonical name (e.g., "search_and_replace" → "edit")
	const resolvedTool = TOOL_ALIASES[tool] ?? tool
	const resolvedIncludedTools = includedTools?.map((t) => TOOL_ALIASES[t] ?? t)

	// Check tool requirements first — explicit disabling takes priority over everything,
	// including ALWAYS_AVAILABLE_TOOLS. This ensures disabledTools works consistently
	// at both the filtering layer and the execution-time validation layer.
	if (toolRequirements && typeof toolRequirements === "object") {
		if (
			(tool in toolRequirements && !toolRequirements[tool]) ||
			(resolvedTool in toolRequirements && !toolRequirements[resolvedTool])
		) {
			return false
		}
	} else if (toolRequirements === false) {
		// If toolRequirements is a boolean false, all tools are disabled
		return false
	}

	// Always allow these tools (unless explicitly disabled above)
	if (ALWAYS_AVAILABLE_TOOLS.includes(tool as any)) {
		return true
	}

	// For now, allow all custom tools in any mode.
	// As a follow-up we should expand the custom tool definition to include mode restrictions.
	if (experiments?.customTools && customToolRegistry.has(tool)) {
		return true
	}

	// Check if this is a dynamic MCP tool (mcp_serverName_toolName)
	// These should be allowed if the mcp group is allowed for the mode
	const isDynamicMcpTool = tool.startsWith("mcp_")

	if (experiments && Object.values(EXPERIMENT_IDS).includes(tool as ExperimentId)) {
		if (!experiments[tool]) {
			return false
		}
	}

	const mode = getModeBySlug(modeSlug, customModes)

	if (!mode) {
		return false
	}

	// Check if tool is in any of the mode's groups and respects any group options
	for (const group of mode.groups) {
		const groupName = getGroupName(group)