browser_file_upload

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

With no annotations, the description carries the full burden of behavioral disclosure. It only states that files are uploaded, with no mention of side effects, cancellation behavior, permissions, or reversibility. The schema adds some detail (e.g., omitting paths cancels the chooser), but the tool description itself is nearly tautological with the name.

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 short sentence, but it is under-specified rather than appropriately concise. It repeats the tool name's intent without adding valuable information, so it does not earn its place as a meaningful contribution.

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 lack of annotations and output schema, the description alone is insufficient to fully understand the tool's behavior. It does not explain when to use it, what happens after upload, or any limitations. The schema covers parameters but not the operational context, leaving the description incomplete.

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 input schema fully documents both parameters with descriptions (100% coverage), so the baseline is 3. The tool description adds no additional parameter meaning beyond what the schema already provides, so it neither improves nor degrades the score.

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 states a specific verb ('Upload') and resource ('files'), and clarifies it handles 'one or multiple files'. The tool name 'browser_file_upload' reinforces the browser context, making the purpose clear. However, it does not differentiate from siblings because no sibling upload tool exists, so it loses the fifth point.

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 guidance is provided on when to use this tool versus alternatives, prerequisites (e.g., needing an active session), or when not to use it. The description only states the action, leaving the agent without contextual decision-making information.

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