Open a batch of files so language servers begin publishing diagnostics for them. Required warm-up before lsp_workspace_diagnostics (which only sees opened files) and before lsp_related_files imported_by. Use a small targeted set rather than the whole workspace.
AI agents call lsp_index_files to retrieve information from Lsp without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool opens files to trigger language server indexing/diagnostics publishing. It reads files into the language server's awareness but does not create, modify, delete, or execute anything. The side effect (diagnostics being published) is an internal LSP state change, not a modification to external data. Most similar to a read/fetch operation.
From the tool's definition Open a batch of files so language servers begin publishing diagnostics for them. Required warm-up before lsp_workspace_diagnostics
Attacks that exploit this kind of access
Open a batch of files so language servers begin publishing diagnostics for them. Required warm-up before lsp_workspace_diagnostics (which only sees opened files) and before lsp_related_files imported_by. Use a small targeted set rather than the whole workspace. It is categorised as a Read tool in the Lsp MCP Server, which means it retrieves data without modifying state.
Register the Lsp MCP server in PolicyLayer and add a rule for lsp_index_files: 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. Nothing to install.
lsp_index_files 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 lsp_index_files 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 lsp_index_files. 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.
lsp_index_files is provided by the Lsp MCP server (lsp-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
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