Activate a plugin MCP server for this session. Fetches its tool definitions and adds them to the available tools. Use list_available_mcps to see what can be activated.
Part of the Clevername server.
Free to start. No card required.
AI agents use activate_mcp to create or modify resources in Clevername. Write operations carry medium risk because an autonomous agent could trigger bulk unintended modifications. Rate limits prevent a single agent session from making hundreds of changes in rapid succession. Argument validation ensures the agent passes expected values.
Without a policy, an AI agent could call activate_mcp repeatedly, creating or modifying resources faster than any human could review. PolicyLayer's rate limiting ensures write operations happen at a controlled pace, and argument validation catches malformed or unexpected inputs before they reach Clevername.
Write tools can modify data. A rate limit prevents runaway bulk operations from AI agents.
{
"version": "1",
"default": "deny",
"tools": {
"activate_mcp": {
"limits": [
{
"counter": "activate_mcp_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}See the full Clevername policy for all 67 tools.
These attack patterns abuse exactly the kind of access activate_mcp gives an agent. Each links to the full case and the policy that stops it:
Other write tools across the catalogue. The same approach applies to each: rate-limit and validate the arguments.
Activate a plugin MCP server for this session. Fetches its tool definitions and adds them to the available tools. Use list_available_mcps to see what can be activated.. It is categorised as a Write tool in the Clevername MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Clevername MCP server in PolicyLayer and add a rule for activate_mcp: 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 Clevername. Nothing to install.
activate_mcp 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 activate_mcp 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 activate_mcp. 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.
activate_mcp is provided by the Clevername MCP server (@clevername/clevername-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 67 Clevername tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
4,600+ MCP servers and 31,000+ tools scanned and risk-classified.