Too Many MCP Tools Warning: How to Fix It (VS Code, Cursor, Claude Code)

A "too many tools" warning means your enabled MCP servers expose more tool definitions than the client will send to the model in one request. In VS Code the message is "Cannot have more than 128 tools per request." The fastest fix is to turn off servers and tools you do not need for the current task. In Claude Code and newer Cursor builds, tool search or on-demand loading handles large tool sets for you.

Checked against: the VS Code "Use tools in chat" docs, Cursor's MCP docs, Cursor's "Dynamic context discovery" post and the Claude Code MCP docs on 2 November 2026. eSEOspace did not reproduce each warning.

What this error means

Each MCP tool has a name, a description and an input schema. Clients send these definitions to the model so it can choose a tool. Some clients cap how many they send. Others load definitions on demand.

Large servers make this easy to hit. A single SaaS server can expose dozens of tools, and three or four servers can pass 100. A user on Cursor's forum reported in March 2025 "an effective limit of 40 tools that can be enabled in total across all MCP servers."

The deeper cost is context. Tool definitions take space in the model's context window on every turn. Our explainer on the context window and too many tools covers why.

Quick fix

1. List what is enabled. Count servers and tools in your client.
2. Turn off servers you do not need for this project or task.
3. Deselect individual tools you never use, such as admin or delete tools.
4. Split by project. Put project-specific servers in the project config, not your global config.
5. Prefer leaner servers. Some vendors offer toolsets or read-only modes. Use them.
6. Start a new chat and check that the warning is gone.

Fix by client / OS

VS Code

The VS Code tools docs give two fixes for "Cannot have more than 128 tools per request.":

• Open the tools picker in the Chat view and "deselect some tools or entire MCP servers to reduce the count." For Local harness sessions, use Configure Tools in the chat input.
• Enable virtual tools with the github.copilot.chat.virtualTools.threshold setting, which manages large tool sets automatically.

Cursor

Cursor's MCP docs say you can toggle a server off in Customize, and disabled servers "won't load or appear in chat." The page frames this as "reducing tool clutter." In January 2026, Cursor's dynamic context discovery post said it now syncs tool descriptions to a folder so the agent starts with only tool names. It reported that this "reduced total agent tokens by 46.9%" in runs that called an MCP tool, in an A/B test. That is Cursor's own figure.

If you still see a tool-limit warning, update Cursor and disable servers you do not need. Enterprise admins can also set tool allowlists.

Claude Code

The Claude Code MCP docs say tool search "keeps MCP context usage low by deferring tool definitions until Claude needs them," and that Claude Code "doesn't impose a fixed per-server tool cap; the practical limit is your context window budget." Control it with ENABLE_TOOL_SEARCH:

To keep a few critical tools always loaded, set "alwaysLoad": true on that server. The docs warn that each up-front tool "consumes context that would otherwise be available for your conversation." Tool descriptions loaded through tool search are cut at 16,384 characters by default, so put the key words near the start.

Claude Desktop and claude.ai

We did not find a documented tool-count warning for Claude's apps. Turning off connectors you do not need in a chat still reduces the tools Claude has to choose from.

Where to find the logs

• VS Code: the error appears in the Chat view; server details are under MCP: List Servers > Show Output.
• Cursor: MCP Logs in the Output panel.
• Claude Code: /context labels deferred tools, and /mcp shows the tool count next to each connected server.

If it still fails

• Tools vanish without a warning. See MCP tools not showing in Cursor.
• The agent picks the wrong tool. Better names help. See tool naming and descriptions.
• You want lower token use. Read tool search and code mode and how to reduce MCP token costs.
• Too many approval prompts with many tools? See approval fatigue.

Plan which tools each role really needs with the MCP tool permission planner. If you build a server with a huge tool list, our MCP development team can help you design a smaller one.

Frequently asked questions