ADD categorical TAGS to existing entities for filtering and organization. Tags are case-sensitive exact-match labels used for quick retrieval with search_knowledge. Common categories: status, priority, type, domain.
AI agents use add_tags to create or update resources in KnowledgeGraph MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your KnowledgeGraph MCP Server environment.
This tool modifies metadata on existing entities by adding tags for organization and filtering. It creates new label associations rather than deleting or destroying data. The change is reversible (tags can be removed), making it Write rather than Destructive. The impact is limited to organizational metadata, not core data integrity, hence low severity.
From the tool's definition Tool description states 'ADD categorical TAGS to existing entities' and is positioned among write-class sibling tools like 'add_observations', 'create_entities', 'create_relations'. The action is reversible via 'remove_tags' sibling tool.
Documented attack patterns abuse exactly the kind of access add_tags gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and KnowledgeGraph MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for add_tags:
{
"version": "1",
"default": "deny",
"tools": {
"add_tags": {
"limits": [
{
"counter": "add_tags_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}add_tags 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 categorical TAGS to existing entities for filtering and organization. Tags are case-sensitive exact-match labels used for quick retrieval with search_knowledge. Common categories: status, priority, type, domain. It is categorised as a Write tool in the KnowledgeGraph MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the KnowledgeGraph MCP Server MCP server in PolicyLayer and add a rule for add_tags: 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 KnowledgeGraph MCP Server. Nothing to install.
add_tags 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_tags 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_tags. 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_tags is provided by the KnowledgeGraph MCP Server MCP server (n-r-w/knowledgegraph-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from KnowledgeGraph 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.
11 KnowledgeGraph MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.