Best Agent Security Tools 2026
Securing agents means three jobs: guarding credentials, vetting the tools they call, and gating the money. Here's the honest stack.
Credential security
Secret scanning (GitGuardian, TruffleHog) for leaked keys.
Rotation and scoped keys per agent.
Tool and MCP vetting
MCP server vetting — source, permissions, paid calls.
Least-privilege tool access.
Spend gating
A spend firewall: deterministic decisions on the money path.
Caps, allowlists, velocity limits — the layer that makes damage impossible.
At a glance
| Layer | Tools | Job |
|---|---|---|
| Credentials | Secret scanning | Find leaks |
| Tools | MCP vetting | Trust review |
| Money | Spend firewall | Gate damage |
FAQ
What's the most important layer?
All three — but the money gate is the one that makes runaways impossible.
Where should I start?
Secret scanning for today, spend rules for tomorrow.
Related
Stop the next $12,400 night.
One API call (or MCP tool) in front of every agent transaction — APPROVED, BLOCKED, or FLAGGED, deterministic, ~5 ms, fully logged.
See plans — from $99/mo Try a live check