Connecting an AI assistant to tools through Model Context Protocol expands what it can access and execute. The NSA’s May 2026 security guidance, version 1.0, provides a useful baseline for reviewing those connections. The agency released the document on May 20, 2026.
Map trust boundaries. Identify which models, clients, servers and tools handle sensitive information. Keep public-data workflows separated from privileged systems, and treat tool responses as untrusted input before another component acts on them.
Restrict execution. Give each tool only the files, APIs and network access its task requires. Use operating-system isolation where appropriate, validate tool parameters, and restrict outbound connections to approved destinations. Local deployment still requires these controls.
Validate authorization. For protected remote servers using OAuth, follow the MCP authorization requirements: verify that access tokens are intended for the receiving server. Use separate credentials for upstream APIs instead of forwarding the client’s token unchanged.
Make actions traceable. Record identities, tool calls, authorization failures and relevant outcomes while keeping credentials out of logs. Review unusual invocation patterns and preserve enough context to investigate unintended actions.
Review integrations regularly. Maintain an inventory of servers, tools and versions, monitor security advisories, and test changes before deployment. Authentication, sandboxing and filtering address different risks; none independently guarantees protection against malicious instructions or data exposure.
For installable agent packages, use our AI skills review checklist.
