AI agents use update_semantic to create or update resources in Lucid — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Lucid environment.
This tool creates or modifies semantic definitions and configuration data (YAML files) reversibly. While it affects system metadata and search indexes, it does not delete data irreversibly, move money, execute arbitrary code, or perform destructive operations. The changes are reversible through subsequent updates, making it a Write-category tool.
From the tool's definition Tool description explicitly states 'Write or update business semantic definitions' and 'Saves to YAML files and automatically updates the BM25 search index.' The verbs 'write' and 'update' combined with 'saves to' confirm data modification capability.
Attacks that exploit this kind of access
Write or update business semantic definitions for tables. Saves to YAML files and automatically updates the BM25 search index. Supports batch updates for multiple tables. It is categorised as a Write tool in the Lucid MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Lucid MCP server in PolicyLayer and add a rule for update_semantic: 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 Lucid. Nothing to install.
update_semantic 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 update_semantic 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 update_semantic. 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.
update_semantic is provided by the Lucid MCP server (wiseriaai/lucid-skill). 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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