Unstructured API MCP Server

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by Unstructured-IO

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invoke_firecrawl_crawlhtml

Start a web crawl job to extract HTML content from URLs and upload results to S3 storage for processing.

Instructions

Start an asynchronous web crawl job using Firecrawl to retrieve HTML content.

Args:
    url: URL to crawl
    s3_uri: S3 URI where results will be uploaded
    limit: Maximum number of pages to crawl (default: 100)

Returns:
    Dictionary with crawl job information including the job ID

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": {
      "url": "<url>",
      "s3_uri": "<s3_uri>"
    },
    "name": "invoke_firecrawl_crawlhtml"
  }
}

Input Schema

Name	Required	Description	Default
`url`	Yes
`s3_uri`	Yes
`limit`	No

Output Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

Changed1 schema field changedv1.0.0Jan 2, 2026

changedOutput schema / (root)

Previous value: -nullNew value: +{
+  "properties": {
+    "result": {
+      "additionalProperties": true,
+      "title": "Result",
+      "type": "object"
+    }
+  },
+  "required": [
+    "result"
+  ],
+  "title": "invoke_firecrawl_crawlhtmlOutput",
+  "type": "object"
+}

First observedMar 24, 2025

TDQS

A3.5/5.0

Behavior3/5

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It mentions the crawl is 'asynchronous' and that results are uploaded to S3, which adds useful context beyond basic parameters. However, it lacks details on permissions, rate limits, error handling, or job lifecycle management, which are important for a tool that starts background jobs.

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

Conciseness5/5

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

The description is well-structured and front-loaded with the core purpose, followed by organized sections for arguments and returns. Every sentence adds value without redundancy, making it easy for an agent to parse quickly and efficiently.

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

Completeness4/5

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

Given the tool's complexity (starting asynchronous jobs) and lack of annotations, the description does a good job covering the basics: purpose, parameters, and return value. With an output schema present, it doesn't need to detail return values. However, it could improve by addressing job management (e.g., linking to status-checking tools) or error scenarios.

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

Parameters4/5

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

Schema description coverage is 0%, so the description must compensate. It provides clear semantics for all three parameters: 'url' as the target to crawl, 's3_uri' as the upload destination, and 'limit' as the page maximum with a default. This adds meaningful context beyond the bare schema, though it doesn't cover validation rules or format specifics.

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

Purpose4/5

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

The description clearly states the tool's purpose: 'Start an asynchronous web crawl job using Firecrawl to retrieve HTML content.' It specifies the verb ('start'), resource ('web crawl job'), and technology ('Firecrawl'), though it doesn't explicitly differentiate from sibling tools like 'invoke_firecrawl_llmtxt' beyond mentioning HTML content retrieval.

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

Usage Guidelines2/5

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

No guidance is provided on when to use this tool versus alternatives. The description mentions retrieving HTML content but doesn't explain when to choose this over 'invoke_firecrawl_llmtxt' or other crawling-related tools like 'check_crawlhtml_status', leaving the agent without context for tool selection.

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