usable-browser-agent-free

browser_download

Download a file to disk and return its local path, bypassing the save dialog. Use for PDFs, exports, and attachments.

Instructions

Download a file to disk WITHOUT the OS save dialog, and return its local path so you can read it. Use for PDFs, exports, attachments — the file lands in the browser's downloads folder.

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>"
    },
    "name": "browser_download"
  }
}

Input Schema

Name	Required	Description
`url`	Yes	Full URL of the file to download.
`timeout`	No	Max ms to wait for completion (default 60000).
`filename`	No	Optional filename (relative to the downloads folder).

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.7.0Sep 9, 2026

TDQS

A4.2/5.0

Behavior4/5

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

With no annotations, the description carries full burden. It discloses key behaviors: no OS dialog, returns local path, and saves to downloads folder. It does not cover potential failure modes (e.g., invalid URL, network issues) or behavior on timeout, but the core behavioral traits are clearly stated and do not contradict anything.

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 two sentences with no fluff. The most critical information (no dialog, returns path) is front-loaded, followed by use cases. It is efficient and well-structured.

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?

For a relatively simple tool with three parameters and no output schema, the description covers the essential purpose, use cases, and expected outcome. It does not address error handling or edge cases, but those are not critical for an agent to invoke the tool correctly in typical scenarios.

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?

Schema description coverage is 100%, so the baseline is 3. The description adds minimal semantic value beyond the schema; it does not clarify parameter usage further (e.g., how filename interacts with the downloads folder). The use-case mention is helpful but not parameter-specific.

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 states the tool's function: downloading a file to disk without the OS save dialog and returning its local path. It distinguishes itself from sibling tools like browser_save_pdf by focusing on URL-based downloads and explicitly mentioning the dialog bypass, which is unique. The use cases (PDFs, exports, attachments) further clarify intent.

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?

It provides clear guidance on when to use the tool ('Use for PDFs, exports, attachments') and explains the outcome (file lands in downloads folder). However, it does not explicitly contrast with alternatives like browser_downloads_list (for listing downloads) or browser_save_pdf (for saving the current page), leaving some inference to the agent.

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

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