browser_scroll

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

No annotations are provided, so the description carries the full burden. It discloses meaningful behavior: the tool replies only once scrolling is at rest, reports when it moved less than requested because of an end or page intervention, and invalidates coordinates afterward. These are strong operational details beyond the schema, though permission or failure-mode behavior is not described.

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 paragraph is front-loaded with the main scrolling model and then layers target selection, return behavior, and post-scroll state. It is dense but efficient for a 14-parameter tool; each clause contributes operational meaning, though the semicolon-heavy structure makes it slightly harder to parse than necessary.

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 complex, annotation-free tool with no output schema, the description covers the key gaps: how target selection works, what scrolling modes exist, what the tool returns (at-rest notification), how partial movement is reported, and that snapshots must be refreshed after scrolling. It is nearly complete, though it could say more about failure or timeout behavior beyond the schema's timeoutMs.

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 100%, so the baseline is 3. The description still adds value by constraining mutually exclusive parameters ('deltaY ... or toY ..., not both'), explaining sign conventions ('positive is down, as scrollTop counts'), and clarifying that emsn -1 applies only when the snapshot offers it. It does not overload schema details but tightens their meaning.

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 verb and resource, 'Scroll', and immediately clarifies the two main modes: relative delta scrolling versus absolute to-position scrolling. It is clearly distinguishable from siblings like browser_click or browser_wait because it defines exactly what scrolling means and how the target is selected.

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?

It gives explicit selection rules: use deltaY or toY, not both; deltaX/toX are the horizontal equivalents; use emsn for independently scrolling panes; use emsn -1 for the whole page only when the snapshot's page position line offers it. It also states that coordinates become void after a scroll and a fresh snapshot is needed, which is a critical usage constraint.

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