browser_screenshot

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

With no annotations provided, the description carries full burden. It discloses capture modes, default vs. full_page vs. ref behavior, and the output_path file-writing behavior. However, it omits any mention of session handling or required permissions, which are relevant for context.

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 concise with three focused sentences. The first sentence states the main purpose and default, the second elaborates modes, the third details output_path. No wordiness or redundancy.

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?

Despite missing session_id and not explicitly stating the default return format (image bytes), the description covers key behaviors and use cases adequately for a low-complexity tool. It is sufficiently complete given no annotations or output schema.

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?

Three of four parameters (full_page, ref, output_path) are explained in detail, adding meaning beyond the bare schema. The session_id parameter is not mentioned, leaving a gap. Overall, it compensates well for the 0% schema coverage.

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 the tool takes a PNG screenshot and distinguishes three capture modes (viewport, full page, single element). This specificity and differentiation from sibling tools like browser_snapshot earn a top score.

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 provides clear context on when to use the output_path option for offloading large images to another tool. However, it does not explicitly mention when not to use this tool, nor does it discuss alternatives beyond the implied scenario.

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