fetch_htmlFetch a URL and return clean HTML with structure preserved and scripts/styles stripped—ideal for site migration and content extraction.
Fetch a URL, return clean HTML (structure kept, scripts/styles stripped). Free. Site migration.
| Name | Required | Description | Default |
|---|---|---|---|
| url | Yes | Page URL. | |
| headers | No | Headers to forward (Authorization, Cookie…). | |
| maxChars | No | Default 16000, max 64000. |
Changes observed during successful MCP inspections.
v0.1.1Input schema / properties / headersAdded value: +{
+ "description": "Headers to forward (Authorization, Cookie…).",
+ "type": "object"
+}Input schema / properties / maxChars / descriptionPrevious value: -"Max characters to return (default 16000, max 64000)."New value: +"Default 16000, max 64000."Input schema / properties / url / descriptionPrevious value: -"The URL to fetch (http:// or https://)."New value: +"Page URL."v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, and the description usefully adds the output-shaping behavior (scripts and styles stripped, DOM structure preserved). It says nothing about truncation beyond maxChars, redirect handling, JS-rendered pages, or failure modes — meaningful gaps for a fetch tool with no output schema.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The core clause is front-loaded and efficient, but the sentence fragments 'Free.' and 'Site migration.' are dangling and cost clarity rather than adding it. Two words of ambiguity where a short clarifying clause would have earned its space.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a read-only fetch with no output schema, the description conveys the return shape (cleaned HTML) but leaves out truncation semantics beyond the schema's maxChars, large-page behavior, and private/authenticated page handling that the 'Authorization, Cookie' header param implies is supported.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 100%, so all three parameters including the nested headers object are documented in the schema itself. The description adds no parameter meaning beyond that, which is acceptable but not additive.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
States a specific verb and resource (fetch a URL) and, importantly, specifies the transformation applied (clean HTML, structure kept, scripts/styles stripped), which distinguishes it from html_to_markdown and fetch_extract. The trailing fragments 'Free. Site migration.' are cryptic but the core purpose is unambiguous.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
'Free' signals a cost preference and 'Site migration' hints at a scenario, but neither states when to choose this over html_to_markdown, fetch_extract, or fetch_metadata. No exclusions, prerequisites, or alternative-routing guidance are given despite five closely related siblings.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.