rohitg00/agentmemory · error · Error

Unknown tool: ${v.tool}

Error message

Unknown tool: ${v.tool}

What it means

The standalone MCP server's proxy handler `handleProxy` dispatches a validated tool call through a switch on the tool name and throws this error when no case matches. It means the MCP client requested a tool that is neither one of the proxy-backed tools nor handled locally. It guards against invoking tool names that were never registered, including typos and tools removed in newer versions.

Source

Thrown at src/mcp/standalone.ts:255

      const result = await handle.call("/agentmemory/governance/memories", {
        method: "DELETE",
        body: JSON.stringify({ memoryIds: v.memoryIds, reason: v.reason }),
      });
      return textResponse(result);
    }
    case "memory_export": {
      const result = await handle.call("/agentmemory/export", { method: "GET" });
      return textResponse(result, true);
    }
    case "memory_audit": {
      const result = await handle.call(
        `/agentmemory/audit?limit=${v.limit}`,
        { method: "GET" },
      );
      return textResponse(result, true);
    }
    default:
      throw new Error(`Unknown tool: ${v.tool}`);
  }
}

async function handleLocal(
  v: Validated,
  kvInstance: InMemoryKV,
): Promise<{ content: Array<{ type: string; text: string }> }> {
  switch (v.tool) {
    case "memory_save": {
      const id = generateId("mem");
      const isoNow = new Date().toISOString();
      await kvInstance.set("mem:memories", id, {
        id,
        type: v.type,
        title: (v.content || "").slice(0, 80),
        content: v.content,
        concepts: v.concepts,
        files: v.files,

View on GitHub (pinned to e04ba88819)

Solutions

1. Call `tools/list` (or inspect handleProxy's switch in src/mcp/standalone.ts) to get the exact supported tool names and correct the caller.
2. Fix typos in the tool name — names are exact-match, case-sensitive strings like `memory_save`.
3. Update the @agentmemory MCP server to a version matching your client's tool list, or downgrade the client.
4. If you need a tool that genuinely doesn't exist, implement it in handleProxy or run the full agentmemory server instead of the standalone bundle.

Example fix

// before
await callTool("memory_search_all", { query: "x" });
// after
// use a real tool name from tools/list, e.g.:
await callTool("memory_recall", { query: "x" });

const SUPPORTED = new Set(["memory_save", "memory_recall", "memory_search" /* ...from tools/list */]);
function assertKnownTool(tool: string) {
  if (!SUPPORTED.has(tool)) throw new Error(`Tool "${tool}" not supported by this server; call tools/list`);
}

function isKnownTool(tool: string, known: readonly string[]): tool is typeof known[number] {
  return (known as readonly string[]).includes(tool);
}

try {
  return await callTool(toolName, args);
} catch (e) {
  if (e instanceof Error && e.message.startsWith("Unknown tool:")) {
    const list = await callTool("tools/list"); // or handle tools/list request
    throw new Error(`Unknown tool "${toolName}". Available: ${JSON.stringify(list)}`);
  }
  throw e;
}

When it happens

Trigger: Calling an MCP tool via `mcp::tools::call` (or tools/call over the MCP transport) whose name is in the validated set but has no `case` in handleProxy's switch — e.g. a typo like `memory_retrive`, a tool from a newer agentmemory release than the server, or a custom tool name invented by the caller.

Common situations: An LLM agent hallucinates a plausible tool name; a client hardcodes tool names after an upgrade where tools were renamed; calling the proxy path with a tool that only exists in the full server, while the standalone bundle only wired a subset into handleProxy.

Related errors

• Unknown tool: ${toolName} (local fallback supports only ${[.
• mem::search: token_budget must be a positive integer
• Unknown tool: ${toolName}
• content is required
• query is required

AI-assisted analysis of rohitg00/agentmemory@e04ba88819 (2026-08-30). Data as JSON: /api/errors/ee10dc79b9b2575b. Report an issue: GitHub.