This record as markdown: /tools/io-github-dave-london-npm/clippy.md
What clippy does on Npm
AI agents invoke clippy to trigger actions in Npm. 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 clippy is rated High
The tool runs cargo clippy, which is an external command execution that lints Rust code. It triggers a real process execution whose effects depend on the codebase. While read-like in intent (returning diagnostics), it actually executes an external command, placing it in the Execute category. Misuse could expose code, trigger build side effects, or run in unintended directories.
From the tool's definition 'Runs cargo clippy' — executes an external tool/process against code
Attacks that exploit this kind of access
The rule that runs clippy safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Npm, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For clippy, this is the rule to start with:
clippy 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.
The button opens the PolicyLayer dashboard: create your workspace, connect Npm, apply this rule, and every clippy call is checked against it from then on.
Questions about clippy
Runs cargo clippy and returns structured lint diagnostics. It is categorised as a Execute tool in the Npm MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the Npm MCP server in PolicyLayer and add a rule for clippy: 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 Npm. Nothing to install.
clippy is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the clippy 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 clippy. 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.
clippy is provided by the Npm MCP server (Dave-London/Pare). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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