Append a block of text to the end of an existing page, separated by a blank line. Errors if the page does not exist — use create_page for new pages. The existing page body is read server-side and never round-trips through this conversation, which avoids accidental modification of existing content...
AI agents use append_to_page to create or update resources in Silverbullet — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Silverbullet environment.
This tool writes new data to an existing note page by appending text. It is a Write operation because it modifies a page's content in a reversible way (the appended text can be removed). It does not delete, execute code, or involve financial transactions.
From the tool's definition 'Append a block of text to the end of an existing page' — adds new content to an existing page without deleting or overwriting existing content; reversible by editing the page.
Attacks that exploit this kind of access
Append a block of text to the end of an existing page, separated by a blank line. Errors if the page does not exist — use create_page for new pages. The existing page body is read server-side and never round-trips through this conversation, which avoids accidental modification of existing content. Final page size is capped at 256 KB. Does not return lastModified — append intentionally leaves the caller without a version marker, since you have not seen the full body and so are not in a position to follow up with write_page. Call read_page if you need to. It is categorised as a Write tool in the Silverbullet MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Silverbullet MCP server in PolicyLayer and add a rule for append_to_page: 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 Silverbullet. Nothing to install.
append_to_page 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 append_to_page 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 append_to_page. 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.
append_to_page is provided by the Silverbullet MCP server (xmatthewx/silverbullet-mcp-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.
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