browser_upload_file

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

Annotations already declare destructiveHint=true, openWorldHint=true and non-idempotent behavior, so safety context exists. The description adds virtually nothing beyond them — no note that the named local path must exist, that it interacts with the host filesystem, or what happens if the element is not a valid file input.

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?

A single tight sentence with the action front-loaded. Effectively sized, though the parenthetical overloads it with locator terminology that arguably belongs in usage guidance.

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 destructive, open-world mutation tool with five parameters, no output schema, and no required params, the description omits the prerequisite (ref acquisition), the path/paths semantics, and any failure or side-effect behavior. What an agent needs to call it correctly is largely 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?

The description names ref/selector/text, mapping to three of the five parameters, but says nothing about the single-vs-multiple file distinction between 'path' and 'paths', which is the most consequential semantic in the schema. With 60% schema coverage, some compensation occurs but the critical path/paths ambiguity is left unresolved.

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+resource ('Upload local file(s)') and mentions the target forms (file input or upload button), which distinguishes it from sibling tools like browser_click or browser_type. The trailing '(ref/selector/text)' is confusingly framed as if those were upload methods rather than element locators, slightly muddying the purpose.

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?

No when-to-use guidance, no exclusions, and no mention of prerequisites such as obtaining a ref from browser_snapshot before calling this. The agent is left to infer the workflow entirely.

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