# Removal of Custom Modes prevents unloading MCP tools (Context Bloat)

**URL:** <https://forum.cursor.com/t/removal-of-custom-modes-prevents-unloading-mcp-tools-context-bloat/145067>\
**Category:** Feature Requests\
**Created:** [December 2, 2025, 9:37pm UTC](https://forum.cursor.com/t/removal-of-custom-modes-prevents-unloading-mcp-tools-context-bloat/145067 "2025-12-02T21:37:09Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![nick-youngblut](https://sea3.discourse-cdn.com/cursor1/user_avatar/forum.cursor.com/nick-youngblut/32/53312_2.png) [@nick-youngblut](https://forum.cursor.com/u/nick-youngblut)\
**Post date:** [December 2, 2025, 9:37pm UTC](https://forum.cursor.com/t/removal-of-custom-modes-prevents-unloading-mcp-tools-context-bloat/145067/1 "2025-12-02T21:37:09Z")

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### Feature request for product/service

Cursor IDE

### Describe the request

Description: With the deprecation of Custom Modes in favor of Slash Commands/Rules, we have lost the ability to physically unload MCP tools from the context window per chat.

The Problem: Slash commands (/backend) only provide prompt instructions to ignore a tool. They do not remove the tool’s schema from the system prompt.

- Token Cost: I have heavy MCP servers (Postgres, Figma) that consume significant context just by being enabled.

- Hallucinations: The Agent still “sees” the tools and sometimes tries to call them despite instructions.

- Friction: The only workaround currently is to manually toggle MCP servers On/Off in global settings every time I switch tasks.

The Request: Please allow Slash Commands or .cursorrules to programmatically enable/disable specific MCP servers.

- Example: A config in .cursor/commands/backend.md like mcp\_enabled: [‘postgres’] that ensures ONLY Postgres tools are loaded into the context window for that chat.

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**Author:** ![jabooth](https://avatars.discourse-cdn.com/v4/letter/j/c57346/32.png) [@jabooth](https://forum.cursor.com/u/jabooth)\
**Post date:** [December 2, 2025, 9:56pm UTC](https://forum.cursor.com/t/removal-of-custom-modes-prevents-unloading-mcp-tools-context-bloat/145067/2 "2025-12-02T21:56:52Z")

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In general, I think there are a lot of opportunities to expand the project .cursor configuration capabilities. I think the big challenge is going to be balancing the natural language approach used there with the definitive lock down capabilities we want/don’t want. If we cant do that with a rule .mdc or a command .md, MAYBE we could add a .cursor/commands/backend.cfg as json/xml with block/allow logic.. easily expandable, but explicit enough to contain token bloat and mitigate workflow friction? If the matching rule or command is used/called, the associated .cfg is honored by the IDE (not the LLM) and tool access is constrained while tokens are preserved.