scroll

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

With no annotations provided, the description carries the behavioral disclosure burden. It discloses that the tool scrolls from the center of the screen, uses semantic directions, and is implemented as a wrapper around 'swipe'. This gives the agent an accurate mental model of what will happen, though it does not describe edge cases such as failure behavior or when scrolling may have no effect.

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 two concise sentences: the first states the core behavior, and the second positions the tool relative to 'swipe' and 'scroll_to'. Every sentence earns its place with no filler or redundant restating of the tool name.

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 low-complexity tool, the description covers purpose, behavior, and the main alternative, and an agent can call the tool successfully with just the required 'direction' parameter. However, with no annotations and no parameter descriptions for 'amount' and 'serial', the description is not fully complete for agents that need to customize those values.

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?

The schema has 0% description coverage, so the description should compensate. It does add meaning for the required 'direction' parameter by listing valid values ('up', 'down', 'left', 'right'), but it says nothing about 'amount' or 'serial'. These remain unexplained, leaving the agent without enough information to intentionally customize them.

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 ('scroll from the middle of the screen') with concrete valid directions ('up', 'down', 'left', 'right'). It also clarifies that this tool is a convenience wrapper around 'swipe' and distinguishes it from 'scroll_to', making its role among siblings clear.

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 explicitly says this is a convenience wrapper around 'swipe' with semantic directions, implying when to prefer it over a raw swipe. It also directly states that if the goal is to scroll to specific text, the agent should use 'scroll_to' instead, which is a clear when-not-to-use instruction.

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