Paginate highlights back to target date with synced range optimization
AI agents call readwise_backfill_highlights to retrieve information from Readwise MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
The tool appears to fetch and paginate through highlights going back to a target date, which is a read/retrieval operation. The 'synced range optimization' may involve writing state (similar to readwise_init_ranges and readwise_reset_state siblings), but the primary action described is data retrieval. Confidence is moderate because the description is brief and the state management aspect could involve writes.
From the tool's definition 'Paginate highlights back to target date' and 'synced range optimization' suggest retrieving/querying historical highlight data
Attacks that exploit this kind of access
Paginate highlights back to target date with synced range optimization. It is categorised as a Read tool in the Readwise MCP Server MCP Server, which means it retrieves data without modifying state.
Register the Readwise MCP Server MCP server in PolicyLayer and add a rule for readwise_backfill_highlights: 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 Readwise MCP Server. Nothing to install.
readwise_backfill_highlights is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the readwise_backfill_highlights 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 readwise_backfill_highlights. 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.
readwise_backfill_highlights is provided by the Readwise MCP Server MCP server (ngpestelos/readwise-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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