capture_screenshot

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

With no annotations, the description carries full behavioral burden. It discloses the CDP capture method (avoids font-loading hangs), file save location (evidence_assets/), return format (inline PNG + text summary), and full_page behavior. The description is transparent for a non-destructive tool, though it omits explicit notes on permissions or side effects.

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?

Single compact paragraph organized with semicolons, covering purpose, implementation, parameters, return value, and use cases without redundancy. Every clause provides actionable detail, making it appropriately 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?

For a two-parameter tool with no output schema or annotations, the description is fully self-contained: it describes what the tool does, how it works, parameter semantics, return payload (summary + image), and ideal use cases. No critical gaps remain.

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 descriptions are absent (0% coverage), so the description fully compensates by explaining both parameters: filename defaults to a timestamp and auto-appends .png, while full_page controls viewport vs. entire page capture. This adds significant meaning beyond the raw schema.

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?

Description clearly states '截取当前页面截图' (capture current page screenshot) with specific CDP implementation, distinguishing it from sibling tools like analyze_current_page or start_recording. The tool's scope and return format (PNG) are explicit, making its purpose unambiguous.

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?

Provides clear use cases with '用于视觉证据、页面状态留档、UI 断言前的实况确认' (used for visual evidence, page status archiving, and live confirmation before UI assertions). While it gives strong context, it does not explicitly exclude alternatives or name sibling tools for comparison.

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