AI agents call lean_get_widget_source to retrieve information from Lean LSP MCP without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
The 'get_' prefix indicates data retrieval with no modification capability. Widget source retrieval in a theorem prover context is informational access only. No side effects, modifications, deletions, or external operations are implied. Confidence is moderate due to empty description, but the context of Lean LSP and naming convention strongly suggest a Read-only operation.
From the tool's definition Tool name 'lean_get_widget_source' suggests retrieval of widget source code/definitions. No description provided, but in context of Lean LSP (Language Server Protocol) and sibling tool 'lean_get_widgets', this appears to be a data retrieval operation.
Documented attack patterns abuse exactly the kind of access lean_get_widget_source gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Lean LSP MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for lean_get_widget_source:
{
"version": "1",
"default": "deny",
"tools": {
"lean_get_widget_source": {}
}
}lean_get_widget_source is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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lean_get_widget_source. It is categorised as a Read tool in the Lean LSP MCP MCP Server, which means it retrieves data without modifying state.
Register the Lean LSP MCP server in PolicyLayer and add a rule for lean_get_widget_source: 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 Lean LSP MCP. Nothing to install.
lean_get_widget_source is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the lean_get_widget_source 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 lean_get_widget_source. 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.
lean_get_widget_source is provided by the Lean LSP MCP server (ooo0ooo/lean-lsp-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 23 Lean LSP MCP tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
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23 Lean LSP MCP tools catalogued and risk-classified — across an index of 42,500+ MCP servers.