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Mads Hansen
Mads Hansen

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MCP database servers need smaller tool catalogs

The easiest MCP database server to build is also the riskiest:

Expose a broad query tool.
Point it at production.
Trust the model to behave.

That is not a production access model. It is a demo.

For real teams, the tool catalog should be designed with least privilege:

  • workflow-specific tools
  • approved views instead of raw tables
  • per-user and tenant scope
  • read/write separation
  • row, time, and cost budgets
  • redaction before summarization
  • approval gates for mutations
  • structured refusal when scope is missing

The tool list is not just developer convenience. It is part of the permission boundary.

Longer version: Least-privilege tool catalogs for MCP database servers

AI agents do better when the safe path is also the narrow path.

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