Fill a complete form with one call — the preferred way to submit any form with 2+ fields. Each field needs ref or CSS selector plus value. Supports text inputs, <select> (by value or visible label), checkboxes (boolean), and radio buttons. Use this INSTEAD of multiple type calls or evaluate-setti...
Part of the Chrome MCP server. Enforce policies on this tool with Intercept, the open-source MCP proxy.
AI agents use fill_form to create or modify resources in Chrome. Write operations carry medium risk because an autonomous agent could trigger bulk unintended modifications. Rate limits prevent a single agent session from making hundreds of changes in rapid succession. Argument validation ensures the agent passes expected values.
Without a policy, an AI agent could call fill_form repeatedly, creating or modifying resources faster than any human could review. Intercept's rate limiting ensures write operations happen at a controlled pace, and argument validation catches malformed or unexpected inputs before they reach Chrome.
Write tools can modify data. A rate limit prevents runaway bulk operations from AI agents.
tools:
fill_form:
rules:
- action: allow
rate_limit:
max: 30
window: 60See the full Chrome policy for all 23 tools.
Agents calling write-class tools like fill_form have been implicated in these attack patterns. Read the full case and prevention policy for each:
Other tools in the Write risk category across the catalogue. The same policy patterns (rate-limit, validate) apply to each.
Fill a complete form with one call — the preferred way to submit any form with 2+ fields. Each field needs ref or CSS selector plus value. Supports text inputs, <select> (by value or visible label), checkboxes (boolean), and radio buttons. Use this INSTEAD of multiple type calls or evaluate-setting select.value: one round-trip, partial errors do not abort, each field reports its own status. On per-field errors, call view_page and retry the failing fields — DO NOT escape to evaluate(querySelector) to patch individual fields; it bypasses framework state management (React, Vue) and hides real bugs.. It is categorised as a Write tool in the Chrome MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Add a rule in your Intercept YAML policy under the tools section for fill_form. You can allow, deny, rate-limit, or validate arguments. Then run Intercept as a proxy in front of the Chrome MCP server.
fill_form 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_form rule in your Intercept 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 Intercept policy for fill_form. 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_form is provided by the Chrome MCP server (@silbercue/chrome). Intercept sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Open source. One binary. Zero dependencies.
npx -y @policylayer/intercept