AI agents use pin_item to create or update resources in Maccy Clipboard MCP — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Maccy Clipboard MCP environment.
This tool modifies clipboard item state by pinning it, which is a reversible write operation. It does not delete data (Destructive), execute arbitrary code (Execute), move money (Financial), or merely read data (Read).
From the tool's definition The tool 'pin_item' performs an action that modifies the state of a clipboard item (marking it as pinned for persistence). The description states it 'Pin a clipboard item' which indicates creating or modifying metadata associated with clipboard data.
Documented attack patterns abuse exactly the kind of access pin_item gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Maccy Clipboard MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for pin_item:
{
"version": "1",
"default": "deny",
"tools": {
"pin_item": {
"limits": [
{
"counter": "pin_item_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}pin_item 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.
Free to start. No card required.
Pin a clipboard item for persistence. It is categorised as a Write tool in the Maccy Clipboard MCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Maccy Clipboard MCP server in PolicyLayer and add a rule for pin_item: 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 Maccy Clipboard MCP. Nothing to install.
pin_item 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 pin_item 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 pin_item. 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.
pin_item is provided by the Maccy Clipboard MCP server (vlad-ds/maccy-clipboard-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Maccy Clipboard MCP, 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.
8 Maccy Clipboard MCP tools catalogued and risk-classified — across an index of 43,000+ MCP servers.