browser_upload_file

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

No annotations are present, so the description carries the behavioral burden. It usefully discloses the main mechanism (Chrome Debugger API, no file dialog), but it does not mention side effects, whether the current input selection is replaced, event firing, or return behavior. Valuable but not comprehensive.

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 tight sentences: the first states purpose and mechanism, the second routes to the sibling for the alternative case. Every sentence earns its place with no filler.

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?

For a straightforward file-upload primitive with full schema coverage and no output schema, the description gives the essential invocation context and the relevant alternative. It could mention return values or selection-replacement behavior, but nothing required to call and distinguish the tool is 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 description coverage is 100%, so the schema already explains file, files, and selector. The tool description adds no parameter-level meaning, which is acceptable under the baseline for full schema coverage.

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?

Opens with a specific verb+resource: uploads a file to an input[type=file] element, and immediately differentiates from the drag-drop sibling. An agent can tell this from browser_drop_file without inspecting sibling schemas.

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 description explicitly names browser_drop_file as the alternative and gives the condition that selects it (drag-drop zones without a visible file input). It also clarifies programmatic CDP upload, so the agent knows when this tool is intended.

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