With five MCP servers configured, the Agent keeps reaching for an issue-tracker tool in the middle of an unrelated refactor. What does that behaviour reflect, and which lever changes it?

The principle — The configured tool surface is live by default. Agent picks up MCP tools automatically and uses them when relevant, so you shape its behaviour by narrowing that surface rather than by naming tools in each prompt.

Why the key is correct — With five servers installed, every tool they expose is a candidate on every turn, and an issue-tracker tool surfacing during a refactor is the system applying a relevance judgement you happen to disagree with. The lever is the tools list at the top of the chat panel: click a tool name to switch it off, or disable the whole server from Customize. Asking for a specific tool by name still works when you do want one.

Why the others are wrong — Requiring an explicit mention before a tool may run would rule out automatic use altogether, and it is the belief that leads people to rewrite their prompts hunting for the phrase that summoned the tool. A per-session quota of calls is invented; relevance drives use, not a schedule. And the order of entries in mcp.json is not a selection mechanism, so reordering the file changes nothing about which tool gets picked.

Remember this — Install narrowly. Each extra server widens the surface the Agent chooses from, and the quickest fix for a distracted Agent is switching tools off for that conversation.

Sources — Cursor's MCP integrations documentation.