AI agents use update_relationship_type 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 updates relationship type definitions in the ontology, which is a Write operation—it modifies existing data structures reversibly without deleting them or executing arbitrary code. The blast radius is moderate because renaming relationship types could break references in dependent ontology items or queries, but the operation is non-destructive and can be reverted.
From the tool's definition Tool description states 'Rename a relationship type' which modifies metadata. Server description confirms 'full CRUD control' of ontology items including 'relationships'. Renaming is a reversible modification operation.
Documented attack patterns abuse exactly the kind of access update_relationship_type 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_relationship_type:
{
"version": "1",
"default": "deny",
"tools": {
"update_relationship_type": {
"limits": [
{
"counter": "update_relationship_type_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
} update_relationship_type 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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Rename a relationship type. 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_relationship_type: 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_relationship_type 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_relationship_type 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_relationship_type. 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_relationship_type 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.