scroll

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

The description goes well beyond the readOnlyHint annotation by disclosing stateful behavior (remembers position across calls), output reporting (reachable/remaining content), and virtualized container handling. This transparency helps agents anticipate side effects and results.

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 dense sentences that efficiently enumerate modes, statefulness, and output characteristics without redundancy. It is front-loaded with the primary action and maintains a clear structure.

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 major behaviors and output, but omits parameter-level details and edge cases. Given the complexity of multiple scroll modes and stateful behavior, it is mostly complete but could benefit from explicit parameter mappings and examples.

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% parameter description coverage, and the description only vaguely hints at action, amount, and location. It does not define the page, timeout_ms, or the structure of the location object, failing to compensate for the missing schema details.

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 explicitly states the tool scrolls by amount, to an element, to the end, or within a container, and introduces a next-chunk mode. It clearly identifies the action and its variants, leaving no ambiguity about the tool's purpose.

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 when to use the next-chunk mode for long pages, but it does not explicitly contrast with sibling tools like navigate or find_elements. It offers clear context for usage but lacks explicit alternatives or exclusions.

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