MCP Lens for DeepSeek Harness
A DeepSeek Harness plugin that replaces loading every connected MCP server's full tool schema with two model-facing tools, one that searches across servers for relevant tools and one that calls a specific tool by name.
MCP Lens gives DeepSeek Harness two tools: one finds relevant tools and returns their exact input schemas, and the other invokes a specific server and tool and returns its result, including structured data that stays available for later calls in the same conversation.
In a 1,000-tool test fixture, the two standing tool definitions occupy about 1.1 kilobytes of JSON regardless of catalog size, compared with roughly 648 kilobytes for a direct client that loads every schema up front. Remote schemas only enter the conversation once a search returns them, connections open on demand, and repeated searches reuse the catalog index.
The plugin targets catalogs of dozens to thousands of tools spread across many MCP servers; for a handful of tools used on nearly every request, the project recommends the official direct MCP client instead. It requires Node.js 22.19 or newer and a matching DeepSeek Harness version.