add_observations | PolicyLayer

WHAT IT DOES

What add_observations does on MCP DuckDB Knowledge Graph Memory Server

AI agents use add_observations to create or update resources in MCP DuckDB Knowledge Graph Memory Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your MCP DuckDB Knowledge Graph Memory Server environment.

THE RISK

Medium Risk

Why add_observations needs a policy

This tool creates or modifies data (observations attached to entities) but does not delete or irreversibly destroy data, nor does it execute arbitrary code or move money. It is reversible (observations can be deleted via sibling tool delete_observations).

From the tool's definition The tool is named 'add_observations' and described as 'Add new observations to existing entities in the knowledge graph'. This creates or appends new data to existing entities, modifying the knowledge graph state reversibly.

Documented attack patterns abuse exactly the kind of access add_observations gives an agent:

POLICY

How to control add_observations

PolicyLayer is an MCP gateway — it sits between your AI agents and MCP DuckDB Knowledge Graph Memory Server, and nothing reaches the server without passing your rules. This is the rule we recommend for add_observations:

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "add_observations": {
      "limits": [
        {
          "counter": "add_observations_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

add_observations 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.

Create a free account and register MCP DuckDB Knowledge Graph Memory Server — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

LIMIT THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More MCP DuckDB Knowledge Graph Memory Server tools

Destructive delete_entities Delete multiple entities and their associated relations from the knowledge graph Destructive delete_observations Delete specific observations from entities in the knowledge graph Destructive delete_relations Delete multiple relations from the knowledge graph Write create_entities Create multiple new entities in the knowledge graph Write create_relations Create multiple new relations between entities in the knowledge graph. Relations should be Read search_nodes Search for nodes in the knowledge graph based on a query Read open_nodes Open specific nodes in the knowledge graph by their names

All 8 MCP DuckDB Knowledge Graph Memory Server tools →

Write tools on other servers

M-Team MCP Server download_torrent YouTube MCP Server generate_video_title Android Forensics ADB MCP Server combine_reports 0xarchive web3_signup

Go deeper

The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Argument validation → Checking tool call arguments against schema and policy before they run.
Scoped token → Per-person credentials that grant a defined subset of servers and tools.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about add_observations

What does the add_observations tool do? +

Add new observations to existing entities in the knowledge graph. It is categorised as a Write tool in the MCP DuckDB Knowledge Graph Memory Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on add_observations? +

Register the MCP DuckDB Knowledge Graph Memory Server MCP server in PolicyLayer and add a rule for add_observations: 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 MCP DuckDB Knowledge Graph Memory Server. Nothing to install.

What risk level is add_observations? +

add_observations is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit add_observations? +

Yes. Add a rate_limit block to the add_observations 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.

How do I block add_observations completely? +

Set action: deny in the PolicyLayer policy for add_observations. 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.

What MCP server provides add_observations? +

add_observations is provided by the MCP DuckDB Knowledge Graph Memory Server MCP server (izumisy/mcp-duckdb-memory-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every MCP DuckDB Knowledge Graph Memory Server tool call.

Start from MCP DuckDB Knowledge Graph Memory Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →

Free to start. No card required.

8 MCP DuckDB Knowledge Graph Memory Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.