Think Tool MCP Server

Official implementation of Anthropic's "think" tool as an MCP server - Dramatically improve Claude's reasoning capabilities with structured thinking.

What is the Think Tool?

This MCP server implements the exact "think" tool that Anthropic introduced in their engineering blog post. The Think Tool provides Claude with a dedicated space for structured reasoning during complex problem-solving tasks, enabling more thoughtful, accurate, and reliable responses.

Proven Performance Benefits

Anthropic's research demonstrates remarkable improvements when using the "think" tool:

54% improvement in complex customer service tasks
Significantly better adherence to detailed policies and guidelines
Enhanced consistency across multiple trials of the same task
Improved performance on software engineering benchmarks
Minimal implementation overhead compared to other enhancement techniques

The "think" tool excels where other approaches fall short:

Better than extended thinking for cases requiring complex tool chains
More effective than baseline prompting for policy-heavy scenarios
Especially powerful when paired with optimized prompting

Quick Install

For Claude Desktop

npx -y @smithery/cli@latest install @PhillipRt/think-mcp-server --client claude --config "{}"

For Cursor

npx -y @smithery/cli@latest install @PhillipRt/think-mcp-server --client cursor --config "{}"

How It Works

The "think" tool implements the exact mechanism described in Anthropic's engineering blog. Unlike extended thinking (which happens before Claude starts responding), the "think" tool allows Claude to pause and reflect during its response generation.

Key mechanism: The tool doesn't perform any external actions or retrieve new information - it simply provides Claude with a dedicated scratchpad to work through reasoning step-by-step, which dramatically improves performance on complex tasks.

When Claude uses the "think" tool:

It pauses to organize thoughts before continuing a complex reasoning chain
It creates a structured approach to multi-step problems
It verifies policy compliance more thoroughly and consistently
It carefully analyzes tool outputs before deciding next steps
It maintains better context awareness across long interactions

When to Use the Think Tool

The "think" tool is especially valuable when:

Working with other MCP tools - Great for analyzing outputs from databases, filesystems, or APIs
Following complex policies - Perfect for customer service, legal, or compliance scenarios
Making sequential decisions - Ideal for workflows where later steps depend on earlier ones
Processing web search results - Helps Claude synthesize information from multiple sources
Solving coding challenges - Improves success rates on software engineering tasks

System Prompt for Optimal Results

Anthropic's research shows that combining the "think" tool with optimized prompting delivers the strongest performance improvements. For best results, add the following optimized system prompt to your Claude interaction:

For Claude Desktop (Custom Instructions)

Go to Settings > Custom Instructions
Add the following system prompt:

You have access to a "think" tool that provides a dedicated space for structured reasoning. Using this tool significantly improves your performance on complex tasks.

## When to use the think tool

Before taking any action or responding to the user after receiving tool results, use the think tool as a scratchpad to:
- List the specific rules that apply to the current request
- Check if all required information is collected
- Verify that the planned action complies with all policies
- Iterate over tool results for correctness
- Analyze complex information from web searches or other tools
- Plan multi-step approaches before executing them

## How to use the think tool effectively

When using the think tool:
1. Break down complex problems into clearly defined steps
2. Identify key facts, constraints, and requirements
3. Check for gaps in information and plan how to fill them
4. Evaluate multiple approaches before choosing one
5. Verify your reasoning for logical errors or biases

Remember that using the think tool has been shown to improve your performance by up to 54% on complex tasks, especially when working with multiple tools or following detailed policies.

For Cursor (Global Rules)

To add the Think Tool as a Cursor Rule:

Open Cursor Settings
Navigate to General > Rules for AI
Add a new rule with the following content:

After any context change (viewing new files, running commands, or receiving tool outputs), use the "mcp_think" tool to organize your reasoning before responding.

Specifically, always use the think tool when:
- After examining file contents or project structure
- After running terminal commands or analyzing their outputs
- After receiving search results or API responses
- Before making code suggestions or explaining complex concepts
- When transitioning between different parts of a task

When using the think tool:
- List the specific rules or constraints that apply to the current task
- Check if all required information is collected
- Verify that your planned approach is correct
- Break down complex problems into clearly defined steps
- Analyze outputs from other tools thoroughly
- Plan multi-step approaches before executing them

The think tool has been proven to improve performance by up to 54% on complex tasks, especially when working with multiple tools or following detailed policies.

Manual Installation

If you prefer to run the server locally:

Clone the repository:
git clone https://github.com/PhillipRt/think-mcp-server.git cd think-mcp-server
Install dependencies:
npm install
Build and run:
npm run build npm start
Configure Claude Desktop manually:
- Find or create the configuration file:
  - macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
  - Windows: %APPDATA%\Claude\claude_desktop_config.json
- Add your server configuration:
{ "mcpServers": { "think-tool": { "command": "node", "args": ["path/to/think-mcp-server/dist/server.js"] } } }

License

MIT License