Summary
A one-tool server is the cheapest thing you can leave connected.
The standing cost of an MCP connection is its tool definitions, paid on every turn. One tool with two parameters is close to free, which means the calculation is simply whether the results are good — no context budgeting required. That is a rarer property than it sounds; most search servers arrive with a dozen variants you will never call.
What it is
A retrieval service exposed as a single search tool. Fully hosted, with no local package.
What you get
Search — a required query, with an optional maximum result count that defaults to a small ceiling.
Requirements
An API key generated in the Seltz Console, sent as a bearer token or an x-api-key header.
Setup effort
Paste a URL with a key — add the endpoint to your client