ruvnet/ruflo · error

[mcp] zero tools available after listing; skipping MCP flow

Error message

[mcp] zero tools available after listing; skipping MCP flow

What it means

Log warning in runMcpFlow: tool listing across the selected MCP servers returned zero usable tools, so there is nothing to advertise to the model and the MCP flow is skipped (not_applicable).

Source

Thrown at ruflo/src/ruvocal/src/lib/server/textGeneration/mcp/runMcpFlow.ts:306

		logger.info(
			{ model: targetModel.id ?? targetModel.name, resolvedRoute },
			"[mcp] runMcp=false (routing chose non-tools candidate)"
		);
		return "not_applicable";
	}

	try {
		const { tools: oaTools, mapping } = await getOpenAiToolsForMcp(servers, {
			signal: abortSignal,
		});
		try {
			logger.info(
				{ toolCount: oaTools.length, toolNames: oaTools.map((t) => t.function.name) },
				"[mcp] openai tool defs built"
			);
		} catch {}
		if (oaTools.length === 0) {
			logger.warn({}, "[mcp] zero tools available after listing; skipping MCP flow");
			return "not_applicable";
		}

		const { OpenAI } = await import("openai");

		// Capture provider header (x-inference-provider) from the upstream OpenAI-compatible server.
		let providerHeader: string | undefined;
		const captureProviderFetch = async (
			input: RequestInfo | URL,
			init?: RequestInit
		): Promise<Response> => {
			const res = await fetch(input, init);
			const p = res.headers.get("x-inference-provider");
			if (p && !providerHeader) providerHeader = p;
			return res;
		};

		const openai = new OpenAI({

View on GitHub (pinned to fa13ee4ad6)

Solutions

1. Check that the MCP servers expose tools and the list operation succeeds; the MCP flow is skipped when no tools are available.

When it happens

Trigger: Thrown at ruflo/src/ruvocal/src/lib/server/textGeneration/mcp/runMcpFlow.ts:306 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of ruvnet/ruflo@fa13ee4ad6 (2026-08-18). Data as JSON: /api/errors/b20d3407ad28b622. Report an issue: GitHub.