cos · MCP Server & Client Test Environment MCP

WHAT IT DOES

What cos does on MCP Server & Client Test Environment

AI agents invoke cos to trigger actions in MCP Server & Client Test Environment. 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 cos needs a policy

The tool itself appears to be a simple mathematical cosine function (Read/Other), but it exists in a testing environment that includes shell command execution capabilities. Given the minimal description, I classify conservatively. The cosine function itself has no side effects and is a pure mathematical operation, making it effectively a Read/Other operation.

From the tool's definition Server description mentions 'shell command execution' and sibling tool 'run_server_command', but 'cos' tool itself is described only as 'cos of a number'

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

cos Rate-limited

cos 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": {
    "cos": {
      "limits": [
        {
          "counter": "cos_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 MCP Server & Client Test Environment, so you can run agents against it safely.

FAQ

Questions about cos

What does the cos tool do? +

cos of a number. It is categorised as a Execute tool in the MCP Server & Client Test Environment MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on cos? +

Register the MCP Server & Client Test Environment MCP server in PolicyLayer and add a rule for cos: 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 MCP Server & Client Test Environment. Nothing to install.

What risk level is cos? +

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

Can I rate-limit cos? +

Yes. Add a rate_limit block to the cos 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 cos completely? +

Set action: deny in the PolicyLayer policy for cos. 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 cos? +

cos is provided by the MCP Server & Client Test Environment MCP server (mayur11235/lets-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.