build_project · Foundry MCP Project MCP: Risk & Policy

WHAT IT DOES

What build_project does on Foundry MCP Project

AI agents invoke build_project to trigger actions in Foundry MCP Project. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why build_project needs a policy

Build operations execute code compilation and potentially code generation in an Ethereum development environment (Foundry). The effects depend on project configuration and contract code being compiled, making it an Execute action rather than Read or Write. While not immediately destructive or financial, building could trigger side effects from contract compilation logic.

From the tool's definition Tool name is 'build_project' with empty description. Context indicates this is part of a Foundry development server that 'enables interaction with Foundry tools through natural language, allowing users to create projects, build contracts, run tests, and…

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

build_project Rate-limited

build_project stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "build_project": {
      "limits": [
        {
          "counter": "build_project_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Foundry MCP Project, so you can run agents against it safely.

FAQ

Questions about build_project

What does the build_project tool do? +

build_project. It is categorised as a Execute tool in the Foundry MCP Project MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on build_project? +

Register the Foundry MCP Project MCP server in PolicyLayer and add a rule for build_project: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Foundry MCP Project. Nothing to install.

What risk level is build_project? +

build_project is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit build_project? +

Yes. Add a rate_limit block to the build_project rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block build_project completely? +

Set action: deny in the PolicyLayer policy for build_project. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides build_project? +

build_project is provided by the Foundry MCP Project MCP server (lhemerly/foundry-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.