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

Beyond the annotations (destructive, openWorld, non-idempotent), the description adds concrete behavioral constraints — max 10 files, 20 MB each — and, importantly, states that the tool returns a page snapshot (elements and text in view with the same numbering). That return-behavior disclosure is valuable since there is no output schema.

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 compact sentences, front-loaded with the action and immediately followed by file format and limits, then the return shape. Some phrasing is terse to the point of being clunky ("Answers the page after it"), but nothing is wasted.

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 3-parameter mutation tool with full annotation coverage and no output schema, the description covers the action, addressing scheme, size/count limits, and post-call return behavior. Only the prerequisite of how to source a file_id or element number is left implicit.

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 100%, so the schema already documents element, files, and the url/file_id alternatives; the description largely restates those formats and the limits. It adds little meaning beyond the structured fields, which matches the baseline 3.

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 gives a specific verb and resource — "Uploads/puts files" into a file field or upload button addressed by `element` — so the action is unambiguous. It does not explicitly contrast itself with the sibling 'cotlet_browser_upload' vs 'cotlet_upload_file' distinction, though the "element" framing implies the browser context.

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 implied through "element: the element's number from the last read or step answer," which situates it in the read-then-act browser workflow. There is no explicit guidance on when to use this versus cotlet_upload or how to obtain a file_id first, leaving the agent to infer prerequisites.

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