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

With no annotations, the description carries the full disclosure burden. It usefully states the cost (1 mcp_call), but says nothing about side effects on the page viewport, whether an active session is required, what happens if scrolling reaches page bounds, or what is returned.

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 short sentences with the action front-loaded and no filler; the cost note is genuinely useful information. Brevity is achieved, though it comes at the expense of the detail captured in other dimensions.

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?

This is a simple tool but it has three undocumented optional parameters, no annotations, and no output schema. The description omits the session-scoping model and the meaning of amount, which an agent needs to invoke it predictably in a multi-session browser context.

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 description coverage is 0%, so the description must compensate, but it only hints at the direction parameter's 'up'/'down' values. The amount parameter (units/pixels, default 600) and the session parameter (which browser context is scrolled) are entirely undocumented in both schema and description.

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 names a specific action (scroll) and its two directions, so the basic operation is clear. However, it never says what is being scrolled (the active browser page in a given session) or how this differs from sibling browser tools, leaving the agent to infer the target from the name alone.

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?

There is no guidance on when to scroll versus alternatives like browser_navigate or browser_click, and no stated prerequisite such as an active browser session being required. The only additional context is a cost note, which is not usage guidance.

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