Preview what pages would be scraped without actually downloading content. This is a dry-run mode that helps you: - Verify the correct pages will be scraped - Check if llms.txt is detected - Validate CSS selectors before actual scraping - Estimate the scope of a scraping operation Returns a list o...
Part of the MarkGrab server.
Free to start. No card required.
AI agents invoke preview_scrape to trigger processes or run actions in MarkGrab. Execute operations can have side effects beyond the immediate call -- triggering builds, sending notifications, or starting workflows. Rate limits and argument validation are essential to prevent runaway execution.
preview_scrape can trigger processes with real-world consequences. An uncontrolled agent might start dozens of builds, send mass notifications, or kick off expensive compute jobs. PolicyLayer enforces rate limits and validates arguments to keep execution within safe bounds.
Execute tools trigger processes. Rate-limit and validate arguments to prevent unintended side effects.
{
"version": "1",
"default": "deny",
"tools": {
"preview_scrape": {
"limits": [
{
"counter": "preview_scrape_rate",
"window": "minute",
"max": 10,
"scope": "grant"
}
]
}
}
}See the full MarkGrab policy for all 5 tools.
These attack patterns abuse exactly the kind of access preview_scrape gives an agent. Each links to the full case and the policy that stops it:
Other execute tools across the catalogue. The same approach applies to each: rate-limit and validate the arguments.
Preview what pages would be scraped without actually downloading content. This is a dry-run mode that helps you: - Verify the correct pages will be scraped - Check if llms.txt is detected - Validate CSS selectors before actual scraping - Estimate the scope of a scraping operation Returns a list of all pages that would be scraped along with configuration details.. It is categorised as a Execute tool in the MarkGrab MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the MarkGrab MCP server in PolicyLayer and add a rule for preview_scrape: 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 MarkGrab. Nothing to install.
preview_scrape is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the preview_scrape 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 preview_scrape. 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.
preview_scrape is provided by the MarkGrab MCP server (pypi:markgrab). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 5 MarkGrab tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
4,600+ MCP servers and 31,000+ tools scanned and risk-classified.