mcpfoldWhat are MCP tools?
Also: MCP tool, tools
MCP tools are the individual actions an MCP server exposes to a model — each with a name, a description, and a JSON-Schema definition of its inputs.
When a client connects to a server, the server lists its tools. Each tool has a machine-readable schema so the model knows what arguments it takes, and a description so the model knows when to use it. The model can then choose to call a tool, and the server runs it and returns the result.
Every tool a server advertises adds its schema to the model’s context, whether or not it is ever used. Loading many servers can therefore consume a large share of the context window.
mcpfold lets you allow- or deny-list tools per server, so only the tools you actually need are exposed — keeping the context window lean.
Related
mcpfold is an independent, open-source project. The Model Context Protocol is an open standard; mcpfold is not affiliated with or endorsed by the MCP project.