Move a function to a different file using LSP refactoring
AI agents use move_function to create or update resources in LSP MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your LSP MCP Server environment.
Moving a function between files creates new code in the destination and removes it from the source, constituting a reversible modification (Write category). It is not Destructive because the function definition is preserved elsewhere, not deleted; it is not Execute because it does not run arbitrary code or trigger external operations based on variable arguments—it restructures code deterministically.
From the tool's definition Tool description states 'Move a function to a different file' — this modifies code structure by relocating function definitions across files, which is a reversible write operation.
Documented attack patterns abuse exactly the kind of access move_function gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and LSP MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for move_function:
{
"version": "1",
"default": "deny",
"tools": {
"move_function": {
"limits": [
{
"counter": "move_function_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}move_function 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.
Move a function to a different file using LSP refactoring. It is categorised as a Write tool in the LSP MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the LSP MCP Server MCP server in PolicyLayer and add a rule for move_function: 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 LSP MCP Server. Nothing to install.
move_function 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 move_function 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 move_function. 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.
move_function is provided by the LSP MCP Server MCP server (sminnee/lsp-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from LSP 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.
5 LSP MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.