WebMCP tool official reference-app
Risk level
low
10/100

Margin Editor

Margin Editor is an officially published WebMCP tool from OpenAI. Anomity scores its risk at 10 out of 100 (low).

browser:control network:outbound

Analysis summary

Margin Editor is an officially published WebMCP tool from OpenAI. Anomity scores its risk at 10 out of 100 (low).

A local note editor in which the agent has its own identity: it creates notes and responds in the margin as a distinct participant rather than silently editing the user's text. A deliberate demonstration that agent-native does not have to mean agent-invisible.

That identity separation is the interesting security property. When agent output is attributable and spatially separated from human content, prompt-injected text the agent produces is visibly the agent's, not the user's — which matters enormously for documents that later feed other systems. Declared capabilities are browser control and outbound network access. It is catalogued as the design pattern worth copying: mark what the model wrote.

Why this entry scored 10 out of 100

This profile starts at the catalog's neutral base of 50. Because the entry is officially published, trust adjusts the score by -40. The entry declares no high-risk capabilities on its own, so capabilities add nothing. It matches no dangerous capability combinations. The clamped result is 10, placing it in the low band.

See the full scoring formula →

Findings

  • Published by the vendor Trust offset
    Contribution to score: -40

Capabilities

Every capability the entry declares, with the security implication of each.

  • browser:control Browser control
    Drives a browser session. Combined with credential access can impersonate the user on web services.
  • network:outbound Outbound network
    Can make outbound network requests. Required for hosted model providers and remote APIs; also the path for data exfiltration if combined with read access.