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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, open world), so the bar is lower; the description still adds real value by disclosing the lazy-load side effect and by describing the response ('the elements and text in view, with the same numbers'), which compensates for the missing output schema. It leaves undocumented what happens when conflicting parameters are supplied together (e.g. element plus direction and screens).

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?

Front-loaded with the mechanism ('mouse wheel'), then ordered by mode, then the return note — a logical progression with no filler sentences. The telegraphic, backtick-heavy phrasing is dense but each clause carries information, so it stays readable rather than padded.

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 four-parameter, all-optional tool with no output schema, the description covers what it does, its side effects, and roughly what comes back. Remaining gaps are behavioral edge cases (precedence between element and direction/screens, what the shared numbering refers to) rather than core information an agent needs to invoke it.

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 baseline is 3, but the description genuinely adds combinatorial meaning the schema does not: which parameter pairs go together (screens qualifies down/up; element selects a scroll-until mode; inside targets a container instead of the page). The cryptic phrase 'with the same numbers' hints at a shared element-numbering convention without explaining it, keeping this just short of 5.

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 and resource ('Scrolls with the mouse wheel') and enumerates the four supported modes (down/up by screens, top/bottom, until element in view, inside a container), which an agent can map directly onto the enum. It does not explicitly name sibling tools (e.g. cotlet_browser_read, cotlet_browser_wait) or state how it differs from them, so it stops short of full sibling differentiation.

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?

'Content that loads on scroll appears' implies the main motivating use case (lazy-loaded or infinite-scroll content), but the description never states when to choose scroll over cotlet_browser_read, cotlet_browser_wait, or cotlet_browser_find. No exclusions or prerequisites (e.g. a page must already be open) are given, so usage is only implied.

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