browser_upload

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

With no annotations, the description carries the full behavioral burden and falls short. It doesn't say whether existing selections are replaced or appended, whether a change/input event fires, whether upload completion is awaited, or what happens if the selector matches a non-file-input element. The plural 'files' versus the single filePath parameter is also unexplained.

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?

One sentence, front-loaded with verb and action, zero filler. Nothing to trim.

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?

A two-parameter mutation-style tool with no annotations, no output schema, and undocumented parameters needs more than a single clause. Key agent-facing facts — error behavior on bad selectors, whether the file must exist and be reachable by the browser, and post-upload timing — are all missing.

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 and only partly does: 'local files' implies filePath is an on-disk path, and 'CSS selector' labels the selector parameter. It adds nothing on path format (absolute vs relative), existence requirements, or how files map to the single filePath field.

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 ('Attach') and resource ('local files to a file input'), which clearly separates it from browser_type and browser_click in the sibling list. It doesn't name a sibling explicitly, but the file-input framing makes the division of labor obvious.

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?

Usage is only implied: the mention of 'a file input identified by CSS selector' hints that the target must be a file input rather than a generic element. There is no statement of when to prefer this over browser_type/browser_click, no preconditions (e.g., page loaded, input visible), and no exclusions.

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