Search the codebase for code snippets based on semantic meaning or natural language description.
AI agents call semantic_search to retrieve information from Headless Codebase Indexer without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool queries and retrieves code snippets using semantic search—a read-only operation with no side effects. It does not create, modify, delete, execute, or transfer resources. The sibling tools (get_definition, get_file_structure, get_references, index_codebase) reinforce that this server is designed for code comprehension and navigation, not mutation or execution.
From the tool's definition Tool name 'semantic_search' and description stating it 'Search[es] the codebase for code snippets based on semantic meaning or natural language description' indicate retrieval of data with no modification or execution capability.
Attacks that exploit this kind of access
Search the codebase for code snippets based on semantic meaning or natural language description. It is categorised as a Read tool in the Headless Codebase Indexer MCP Server, which means it retrieves data without modifying state.
Register the Headless Codebase Indexer MCP server in PolicyLayer and add a rule for semantic_search: 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 Headless Codebase Indexer. Nothing to install.
semantic_search 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 semantic_search 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 semantic_search. 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.
semantic_search is provided by the Headless Codebase Indexer MCP server (y1hanh/codebase-indexer-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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