upload

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

With no annotations, the description carries the full burden of disclosing behavior, but it only says 'set files' — implying action on a file input. It does not disclose whether this triggers file chooser events, whether paths or base64 are expected, whether it waits, or any side effects. There is no contradiction with annotations because none were provided.

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, front-loaded with the verb and target, containing no filler word. It earns its place for the information it does provide, though it could have carried more behavioral or parameter detail without hurting conciseness.

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?

The description plus schema are sufficient to understand the basic call: set a list of file strings on a selector-targeted file input. However, there is no output schema and no annotations, leaving important practical details unseen, such as how file strings are interpreted and whether multi-file support is available. For a 4-parameter tool, this feels adequate but with a visible gap.

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 75%, so the baseline is 3: the description mostly reinforces the schema's target and files parameters but adds little meaning. The 'files' parameter remains ambiguous in both the schema and description — it does not clarify whether strings are paths, URLs, or base64 data. Thus the description does not fill the semantic gap left by the schema.

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 action (setting files) on a specific resource (an input[type=file]), which clearly differentiates it from siblings like click, fill, and type that act on other element types. It is still short of 5 because it does not explicitly name the sibling alternatives it should be chosen over.

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 provides no guidance on when to use this tool, when not to, or how it relates to the file-input-related capabilities of siblings like fill or type. The usage context must be inferred from the tool name and schema, so the guidance is effectively absent.

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