The MCP trust boundary
Tool access adds a new risk surface to an AI workflow. An agent may receive tool metadata, responses and other content that should be treated as untrusted input.
Four questions for every integration
- Identity: Which principal initiated the tool call?
- Authorization: Is the principal permitted to use this particular tool with these parameters?
- Visibility: Can reviewers reconstruct the request, decision and result?
- Change control: Can new tools or modified descriptions be detected before they are trusted?
Recommended safeguards
Enforce authorization at the tool-serving boundary, not through natural-language instructions alone. Separate high-impact tool calls from read-only operations. Keep secrets out of prompts, redact sensitive audit details and test denial paths as carefully as successful paths.
Build an evidence matrix
Map each scenario to the relevant actor, requested tool, expected security decision and observed outcome. This creates a repeatable process for comparing controls rather than relying on vendor claims alone.
These tutorials are starter editorial examples; test commands and update all claims before public release.