Webflow

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by webflow

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TypeScript

Hybrid

whtml_builder

Insert custom HTML elements and CSS rules into active Webflow pages by specifying a parent element and positioning.

Instructions

Designer Tool - WHTML builder to insert elements from HTML and CSS strings on the current active page. Accepts HTML markup and optional CSS rules, constructs WHTML, and inserts into a parent element.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "siteId": "<siteId>",
      "actions": "<actions>"
    },
    "name": "whtml_builder"
  }
}

Input Schema

Name	Required	Description	Default
`siteId`	Yes	The ID of the site. DO NOT ASSUME site id. ALWAYS ask user for site id if not already provided or known. use sites_list tool to fetch all sites and then ask user to select one of them.
`actions`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

AddedMay 5, 2026

TDQS

A3.8/5.0

Behavior3/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations indicate a write operation (readOnlyHint=false) and potential side effects (openWorldHint=true). The description confirms insertion into a parent element, but fails to elaborate on behaviors like page modification, undo capabilities, or error handling. It adds some context beyond annotations but lacks depth.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is two sentences, front-loaded with the tool category, and clearly conveys the core function. It contains no redundant information, though the 'Designer Tool' prefix is slightly extraneous. Efficient and well-structured.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness3/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The description misses return value information (e.g., what is returned after insertion) and does not mention error conditions or prerequisites. Given no output schema, this is a gap. However, the description covers the main action and required inputs adequately.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The input schema already provides detailed descriptions for siteId and actions (including nested properties), covering 50% coverage. The tool description summarizes 'HTML markup and optional CSS' but does not add new meaning beyond the schema. Baseline score is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly identifies the tool as a 'WHTML builder' that inserts elements from HTML and CSS strings into the active page, distinguishing it from sibling tools like element_builder or component_builder by focusing on raw string inputs.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explicitly states the tool accepts HTML markup and optional CSS rules and operates on the current active page, providing clear context. However, it does not explicitly exclude alternative tools or state when not to use it, but the usage scenario is well implied.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.