Browser Upload File

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It reveals the tool performs an upload, but does not mention side effects, whether it opens a native file dialog, if it supports simple vs. multiple selection, or what happens on invalid paths/timeouts. Important behavior is missing.

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 description is a single concise sentence with no filler words, which is efficient. However, it is so sparse that it fails to convey necessary operational context, making the conciseness a double-edged sword. It earns its place but does not go beyond the minimum.

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?

Given the tool's complexity (3 required params, no output schema, no annotations), the description is grossly incomplete. An agent has no info on how to combine the parameters, what a valid filePath looks like, whether the session must be active, or what to expect on success/failure. This description is inadequate for correct invocation.

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% and the description mentions no parameter details. The three parameters (sessionId, selector, filePaths) are undocumented in both the schema and description. The description does not add any meaning beyond the name itself; an agent must guess what selector means or what filePaths should contain.

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?

The description says 'Upload files to a file input,' which clearly identifies the action (upload) and the target resource (file input). It is distinct from sibling tools like browser_fill (text entry) and browser_select_option (option selection), so an agent can tell what it does without opening schema.

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?

There is no guidance on when to use this tool vs alternatives. For instance, an agent isn't told to use this only for <input type='file'> elements or how it differs from browser_fill or browser_keyboard_type. The context of a required active session and file paths is implied but never stated.

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