update_ontology_definition_raw
AI agents use update_ontology_definition_raw to create or update resources in Fabric Ontology MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Fabric Ontology MCP Server environment.
This tool modifies ontology definitions in Microsoft Fabric, which are structural metadata artifacts. While reversible (Write vs. Destructive), the blast radius is high because corrupted ontology definitions could break downstream data governance, entity resolution, and business intelligence pipelines across a workspace. The 'raw' designation implies reduced validation, increasing risk of malformed definitions.
From the tool's definition Tool name 'update_ontology_definition_raw' indicates modification of ontology definitions. Server description states 'full CRUD control' including entity types and relationships. Sibling tools confirm write operations (add_*, create_*, delete_*).
Documented attack patterns abuse exactly the kind of access update_ontology_definition_raw gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Fabric Ontology MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for update_ontology_definition_raw:
{
"version": "1",
"default": "deny",
"tools": {
"update_ontology_definition_raw": {
"limits": [
{
"counter": "update_ontology_definition_raw_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
} update_ontology_definition_raw 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.
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update_ontology_definition_raw. It is categorised as a Write tool in the Fabric Ontology MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Fabric Ontology MCP Server MCP server in PolicyLayer and add a rule for update_ontology_definition_raw: 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 Fabric Ontology MCP Server. Nothing to install.
update_ontology_definition_raw 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_ontology_definition_raw 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_ontology_definition_raw. 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_ontology_definition_raw is provided by the Fabric Ontology MCP Server MCP server (tmdaidevs/ontology-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Fabric Ontology 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.
45 Fabric Ontology MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.