Grant a user access to an MCP server
AI agents use goclaw_mcp_server_grant_user to create or update resources in GoClaw MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your GoClaw MCP Server environment.
This tool modifies access control by granting a user permissions to an MCP server. It's a Write operation (creating/modifying an access grant), but not Destructive. However, the severity is high because granting unauthorized access to an MCP server could allow an attacker to leverage all tools on that server, representing a significant privilege escalation risk.
From the tool's definition Grant a user access to an MCP server
Documented attack patterns abuse exactly the kind of access goclaw_mcp_server_grant_user gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and GoClaw MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for goclaw_mcp_server_grant_user:
{
"version": "1",
"default": "deny",
"tools": {
"goclaw_mcp_server_grant_user": {
"limits": [
{
"counter": "goclaw_mcp_server_grant_user_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
} goclaw_mcp_server_grant_user stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.
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Grant a user access to an MCP server. It is categorised as a Write tool in the GoClaw MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the GoClaw MCP Server MCP server in PolicyLayer and add a rule for goclaw_mcp_server_grant_user: 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 GoClaw MCP Server. Nothing to install.
goclaw_mcp_server_grant_user is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the goclaw_mcp_server_grant_user 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.
Set action: deny in the PolicyLayer policy for goclaw_mcp_server_grant_user. 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.
goclaw_mcp_server_grant_user is provided by the GoClaw MCP Server MCP server (nextlevelbuilder/goclaw-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from GoClaw MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
66 GoClaw MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.