Capture built page

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

With no annotations, the description carries full burden and discloses key behaviors: reuses Chrome over CDP or copies profile, never asks for/stores credentials, defaults viewport to Figma frame width. However, it does not mention output format or error scenarios.

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?

Four concise sentences front-loading the main purpose, with each sentence adding unique information. No redundancy or unnecessary content.

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?

While it covers behavior and defaults, it omits expected output (no output schema) and prerequisites (e.g., Chrome availability). For a tool with 3 parameters and no output schema, more detail on return values would improve completeness.

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 description adds value beyond schema: explains that viewportWidth defaults to the Figma frame width, and ties runId to capture_design. Schema coverage is 67%, so description compensates with useful context.

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 measures the live page in the user's browser, piercing shadow DOM and same-origin iframes. It distinguishes from siblings like capture_design by specifying it captures the built 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 usage when measuring a live page after building, but does not explicitly state when to use this tool versus alternatives like run_design_qa or build_report. No exclusions or alternative suggestions are given.

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