scroll_until

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

With no annotations, the description carries the burden. It does disclose a useful behavior: one-viewport-page scrolling and early stopping at container boundary to avoid useless swipes. However, it omits the max_scrolls fallback behavior and does not mention other side effects or failure modes.

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 purpose, the second adds a behavioral detail. No wasted words, front-loaded with the main action. It is perfectly sized.

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?

The description covers the core scroll-until semantics and the container-boundary stop condition, but it does not mention the max_scrolls fallback or what happens if neither the target nor the end is reached. With an output schema present, return details are likely covered, but the stop conditions are partially incomplete.

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 input schema provides descriptions for all 4 parameters, so the baseline is 3. The description adds no extra parameter-specific context beyond what is already in the schema, so a score of 3 is appropriate.

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 clearly states a specific action (scroll until target appears) and the resource (semantic target). It distinguishes itself from general swipe/scroll tools by focusing on semantic target discovery, but it does not explicitly differentiate from the sibling tool 'scroll_page'.

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 implies a use case: scroll until a semantic target is found. However, it does not explicitly state when to use this tool versus alternatives like swipe or scroll_page, nor does it provide exclusion criteria or prerequisites.

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