tooltrust-mcp

tooltrust-mcp

Scan MCP servers for prompt injection, data exfiltration, risky permissions, supply-chain threats, and privilege escalation before your agent blindly trusts them.

First run downloads a ~10MB Go binary from GitHub Releases and caches it at ~/.tooltrust-mcp/bin/. Subsequent runs use the cached binary with no download.

What it catches

• Prompt injection and tool poisoning hidden in descriptions
• Excessive permissions such as exec, network, db, and fs
• Supply-chain CVEs and known compromised package versions
• Suspicious npm lifecycle scripts that execute during install
• Suspicious npm IOC dependencies and indicators such as plain-crypto-js, reviewed install-script patterns, malicious domains, and URLs referenced from published package metadata
• Dependency visibility gaps when an MCP server does not expose dependency metadata
• Privilege escalation and arbitrary code execution patterns
• Typosquatting, tool shadowing, and insecure secret handling
• Missing rate-limit, timeout, or retry configuration on risky tools

Quick start

Add to your .mcp.json:

{
  "mcpServers": {
    "tooltrust": {
      "command": "npx",
      "args": ["-y", "tooltrust-mcp"]
    }
  }
}

Then ask your agent: run tooltrust_scan_config

Available tools

Tool	Description
tooltrust_scan_config	Scan all servers in your .mcp.json or ~/.claude.json
tooltrust_scan_server	Scan a specific MCP server
tooltrust_scanner_scan	Scan a JSON blob of tool definitions
tooltrust_lookup	Look up a server's trust grade
tooltrust_list_rules	List built-in tool-definition security rules

Dependency visibility

ToolTrust reports how much dependency evidence it could recover:

• No dependency data
• Declared by MCP metadata
• Verified from local lockfile
• Verified from remote lockfile
• Repo URL available

For local scans, ToolTrust will also try to inspect nearby package-lock.json, pnpm-lock.yaml, yarn.lock, go.sum, and requirements.txt files when it can infer the project root from the launch command.

For GitHub-backed repo_url scans, ToolTrust also inspects remote package-lock.json, pnpm-lock.yaml, yarn.lock, go.sum, and requirements.txt files to recover transitive dependency evidence.

Recent supply-chain incident coverage includes:

• LiteLLM 1.82.7 / 1.82.8 and related TeamPCP compromise indicators
• Axios 1.14.1 / 0.30.4 malicious npm publish
• @cap-js/db-service, @cap-js/postgres, and @cap-js/sqlite compromised release versions
• npm IOC helpers such as plain-crypto-js

Example output

Scan Summary: 14 tools scanned | 13 allowed | 1 need approval | 0 blocked
Tool Grades: A×13  C×1
Findings by Severity: HIGH×1  MEDIUM×14  LOW×1 (16 total)

Flagged Tools:
• search_files  🟡 GRADE C  needs approval
  [AS-002] High: Network access declared
  [AS-011] Low: Missing rate-limit or timeout
  Action now: Keep this tool on manual approval until the risky capabilities are reviewed.

Links

• GitHub: https://github.com/AgentSafe-AI/tooltrust-scanner
• Glama: https://glama.ai/mcp/servers/AgentSafe-AI/tooltrust-scanner
• Directory: https://www.tooltrust.dev/
• Rules: https://github.com/AgentSafe-AI/tooltrust-scanner/blob/main/docs/RULES.md