Add a document reference to an entity type.
AI agents use add_document 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 creates or adds a new document reference to an existing entity type in the Fabric Ontology. While it modifies the ontology structure, the operation is reversible (the reference can be removed or updated later). It does not execute arbitrary code, delete data irreversibly, move money, or merely read data. Write is the appropriate category.
From the tool's definition Tool name is 'add_document' and description states 'Add a document reference to an entity type' — this creates or modifies data by adding a reference, which is a reversible Write operation.
Documented attack patterns abuse exactly the kind of access add_document 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 add_document:
{
"version": "1",
"default": "deny",
"tools": {
"add_document": {
"limits": [
{
"counter": "add_document_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}add_document 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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Add a document reference to an entity 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 add_document: 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.
add_document 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 add_document 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 add_document. 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.
add_document 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.