browser_upload

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 one meaningful constraint: files must come from folders allowed by AGENT_UPLOAD_DIRS. It omits what happens on rejected paths, whether change/submit events fire, or what the response contains, leaving notable behavioral gaps.

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?

Two compact sentences, front-loaded with the action and target, with the security constraint appended. No filler; only slight terseness in the parenthetical that could confuse the ref semantics.

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?

Covers purpose, both modes of targeting, and the folder restriction for a 2-param tool with no annotations or output schema. Missing failure behavior and return-value expectations, so it is adequate but not fully complete.

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 coverage is 0%, so the description must compensate. It explains that 'ref' can target either a file input or a selector opened by clicking that ref, which is real added meaning, and implies 'files' are local paths within allowed folders. It still doesn't state the format of file paths or the array's constraints.

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: attaching local files to an <input type=file> or the selector opened by clicking a ref. This is clearly distinct from sibling tools like browser_click or browser_type. It doesn't explicitly name a sibling alternative, so it stops short of a 5.

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?

The parenthetical clarifies two modes of use (direct input element vs. a selector opened by a click on the ref), which is useful operational context. However, there is no explicit when-to-use/when-not guidance or routing to alternatives, so usage is only implied.

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