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Set one or more files on an using absolute paths for automated browser form uploads. Requires CDP and the top frame.

Instructions

Set one or more files on an using absolute paths on the machine running Chrome. Requires CDP and the top frame.

Input Schema

NameRequiredDescriptionDefault
refNo
filesYes
tabIdNo
frameIdNo
selectorNo

Schema Changelog

Changes observed during successful MCP inspections.

  1. First observedv0.1.3

TDQS

C2.9/5.0
Behavior3/5

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

With no annotations, the description carries the full burden, and it does disclose two non-obvious environment constraints: CDP is required and the operation only works in the top frame. However, it says nothing about side effects on any previously selected files, whether change events fire, permissions, or failure modes, which is a notable gap for a mutation tool.

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?

Two tightly written sentences with the core action front-loaded and prerequisites second; no filler or repetition. Slightly terse on how the target element is identified, but nothing is wasted.

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

Completeness2/5

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

For a 5-parameter mutation tool with 0% schema coverage and no annotations or output schema, the description is thin. It omits how the file input is targeted (ref vs selector), tab/frame selection semantics, overwrite behavior, and error conditions, leaving the agent under-informed before invoking.

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

Parameters2/5

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

Schema description coverage is 0% across 5 parameters, so the description must compensate and largely doesn't. It adds one useful clarification ('absolute paths on the machine running Chrome') for the required files array, but ref, selector, tabId, and frameId — including how the target input is located or which frame/tab is used — remain entirely undocumented.

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 gives a clear verb and a precise target resource: 'Set one or more files on an <input type="file">'. An agent can distinguish this from fill_form/type/select because it names the specific DOM element type it operates on. It stops short of explicitly contrasting itself with those siblings, so a 5 isn't warranted.

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?

The description states a precondition ('Requires CDP and the top frame') but gives no when-to-use versus when-not guidance and names no alternative tools. There is no indication of when this tool should be preferred over e.g. fill_form or how it fails if the prerequisites aren't met.

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