Comparing MCP tool definitions from saved tools/list responses

Описание и применение

mcp‑footprint позволяет измерять размер JSON‑описаний инструментов из каталога MCP, сравнивать их между серверами и визуализировать результаты в HTML‑отчёте.

Задача

Comparing large tool definitions across multiple MCP servers is difficult due to raw JSON size and repetition.

Результат

mcp‑footprint provides repeatable, server‑agnostic measurements of MCP tool definitions, enabling easier catalog review and comparison across servers.

Рабочий процесс

• Save complete tools/list JSON or JSON‑RPC responses from each server.
• Run mcp‑footprint CLI with the saved files to generate footprint.html and footprint.json.
• Review the HTML report to see definition byte counts, proportional maps, and searchable rows.
• Use the report to identify exact definitions, same‑name differences, and similar descriptions across servers.
• Iterate after schema changes to compare measurements.
• Optionally use the CLI as a JavaScript library in custom tooling.

Доказательства

I built mcp-footprint to see how large tool definitions are in a captured MCP catalog and which ones repeat across servers.

Источник

The CLI sorts object keys recursively before serialization. It counts the UTF-8 bytes in each complete canonical tool definition, then counts the canonical aggregate catalog.

Источник

The estimate is ceil(catalogBytes / 4). It's a rough byte-based proxy, not tokenizer output or a measurement of client context use.

Источник