MCP Tool Filtering in OpenAI Agents

Large MCP servers can expose more tools than one agent should see. Filtering improves security, tool selection, and prompt efficiency.

Static filters

Use an allowlist when an agent has a fixed responsibility. For example, a read-only support agent may receive get_order and search_customer but not refund_order.

Dynamic filters

Dynamic filtering can depend on run context, user role, tenant, or workflow stage. Keep the policy deterministic and auditable.

Filtering is not server authorization

A hidden tool should still reject unauthorized direct calls. Client filtering reduces exposure; server authorization enforces access.