Type text into a input, text area or select an option from a <select> element.
AI agents use fill to create or update resources in ReverseCraft DevTools MCP — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your ReverseCraft DevTools MCP environment.
This tool modifies form inputs and select elements, which are reversible changes to webpage state. It does not execute code, delete data, or commit financial transactions. The medium severity reflects that an AI agent could fill forms with malicious or unintended data (e.g., credential injection, spam form submissions), but the impact is limited to form-level modifications that can be corrected.
From the tool's definition Tool name 'fill' and description 'Type text into a input, text area or select an option from a <select> element' indicates creating or modifying form data on a web page.
Documented attack patterns abuse exactly the kind of access fill gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and ReverseCraft DevTools MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for fill:
{
"version": "1",
"default": "deny",
"tools": {
"fill": {
"limits": [
{
"counter": "fill_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}fill stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.
Free to start. No card required.
Type text into a input, text area or select an option from a <select> element. It is categorised as a Write tool in the ReverseCraft DevTools MCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the ReverseCraft DevTools MCP server in PolicyLayer and add a rule for fill: 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 ReverseCraft DevTools MCP. Nothing to install.
fill 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 fill 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 fill. 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.
fill is provided by the ReverseCraft DevTools MCP server (reverse-craft/rc-devtools-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from ReverseCraft DevTools MCP, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
46 ReverseCraft DevTools MCP tools catalogued and risk-classified — across an index of 43,000+ MCP servers.