MCP Context Token Calculator

Inspect public HTTPS MCP tools and estimate their context token footprint.

MCP Context Token Calculator helps developers inspect public HTTPS MCP server endpoints and estimate how much context their exposed tools may add to an AI agent session. Enter a public MCP server URL, run a tools/list inspection, and review a clear breakdown of the server’s tool metadata. The extension estimates each tool’s context footprint and highlights factors that can increase token usage, including long descriptions, large schemas, required parameters, enum values, nesting depth, and metadata warnings. Use it to: - Inspect public HTTPS MCP endpoints directly from your browser - Estimate total context token footprint for an MCP server - Compare individual MCP tools by estimated context weight - Review schema tokens, description tokens, required parameters, enum counts, and nesting depth - Identify metadata patterns that may make tools heavier for AI agents - Quickly validate whether a public MCP endpoint returns usable tools/list metadata This extension is intended for MCP developers, AI agent builders, tool authors, and developer platform teams who want a lightweight way to understand and optimize MCP tool metadata before connecting servers to AI applications. Privacy and network behavior: The extension only sends requests to the HTTPS MCP endpoint entered by the user. It does not require an account, does not collect credentials, and does not use remote JavaScript or WebAssembly. All executable code is bundled with the extension package.