Guide · 06

Tool sets

How many of NexQL's tools your app sees, and why fewer can be better.

Every tool your app lists costs room in the assistant's context window, on every message. NexQL can show all of its tools, or a smaller set suited to the job. Pick with --tools (or NEXQL_MCP_TOOLS).

Set	Tools	For
`query` (default)	22	Asking questions: schema search, run_select, explain_query, exports, connections.
`dba`	27	Looking after a database: health checks, locks, slow queries, index advice, migrations.
`meta`	14	The smallest start. The assistant loads more with discover_tools when it needs them.
`full`	55	Everything.

Each tool's page lists the sets it's in. To pick one, add --tools to the app's config:

{
  "mcpServers": {
    "nexql-mcp": {
      "command": "npx",
      "args": ["-y", "nexql-mcp@latest", "--profile", "mydb", "--tools", "dba"]
    }
  }
}

Sets aren't permissions

A tool set only decides what the assistant is shown. What it may run is decided by the access mode. Write and admin tools stay off the list until a connection allows them, whichever set you choose, and are still checked on every call.

Loading tools on demand

With meta, the assistant starts with the essentials plus discover_tools. When you ask about something outside that set, say lock contention, it searches by keyword ("locks") or category ("dba"), gets the matching tools, and carries on.