---
title: "Gate MCP tool calls behind deterministic policy enforcement with Intercept"
description: "Use Intercept when an MCP-connected agent needs transport-layer policy enforcement for risky tools, argument limits, spend caps, hidden tools, or rate limits before calls reach the upstream server."
verification: "security_reviewed"
source: "https://github.com/PolicyLayer/Intercept"
author: "PolicyLayer"
publisher_type: "organization"
category:
  - "Security & Verification"
framework:
  - "MCP"
tool_ecosystem:
  github_repo: "PolicyLayer/Intercept"
  github_stars: 29
  npm_package: "@policylayer/intercept"
  npm_weekly_downloads: 336
---

# Gate MCP tool calls behind deterministic policy enforcement with Intercept

Use Intercept when an MCP-connected agent needs transport-layer policy enforcement for risky tools, argument limits, spend caps, hidden tools, or rate limits before calls reach the upstream server.

## Prerequisites

Node.js or Go runtime, MCP client, upstream MCP server, YAML policy file

## Installation

Choose whichever fits your setup:

1. Copy this skill folder into your local skills directory.
2. Clone the repo and symlink or copy the skill into your agent workspace.
3. Add the repo as a git submodule if you manage shared skills centrally.
4. Install it through your internal provisioning or packaging workflow.
5. Download the folder directly from GitHub and place it in your skills collection.

Install command or upstream instructions:

```
Install Intercept from npm, Go, or a release binary, write or generate a policy.yaml file, then point your MCP client at the Intercept proxy instead of the upstream server so tool calls flow through policy enforcement.
```

## Documentation

- https://github.com/PolicyLayer/Intercept

## Source

- [Agent Skill Exchange](https://agentskillexchange.com/skills/gate-mcp-tool-calls-behind-deterministic-policy-enforcement-with-intercept/)