Add new observations to existing entities in the knowledge graph
AI agents use add_observations to create or update resources in MCP Memory Server - HTTP Streaming — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your MCP Memory Server - HTTP Streaming environment.
This tool creates or modifies data in a reversible manner (observations can be added to entities), which is characteristic of Write operations. It does not delete data (Destructive), does not execute arbitrary code (Execute), does not move money (Financial), and does not retrieve data without side effects (Read).
From the tool's definition Tool description states it will "Add new observations to existing entities" — a reversible modification operation that creates new data entries within the knowledge graph.
Attacks that exploit this kind of access
Add new observations to existing entities in the knowledge graph. It is categorised as a Write tool in the MCP Memory Server - HTTP Streaming MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the MCP Memory Server - HTTP Streaming 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 Memory Server - HTTP Streaming. Nothing to install.
add_observations 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_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.
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.
add_observations is provided by the MCP Memory Server - HTTP Streaming MCP server (songlairui/mcp-memory-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
Teams ship this data inside their own products. See what a licence covers →