page_screenshot

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

Beyond the readOnlyHint annotation, the description discloses that screenshots are taken after JavaScript execution and that full_page controls viewport vs. full scrollable page. This adds valuable behavioral context. No contradictions with annotations exist.

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 and well-structured: a one-sentence purpose, followed by use cases in a sentence, then an Args list. Every sentence adds value with no redundancy or unnecessary detail.

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 simple tool with no output schema, this description covers the main aspects: what it does, common use cases, key arguments, and a behavioral note. However, it omits any explanation of the 'config' parameter and does not describe the return value or output format, leaving some contextual gaps.

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 Args section explains 'url' and 'full_page' with meaningful descriptions, partially compensating for the 0% schema coverage. However, the 'config' parameter from the schema is completely omitted, leaving its purpose unclear. The description does not fully compensate for all parameters.

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 opens with a specific verb+resource: 'Capture a screenshot of a webpage.' It further specifies 'after JavaScript execution,' distinguishing it from simple scraping tools like content_scrape or js_scrape. This clearly differentiates the tool from sibling tools.

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 lists explicit use cases: 'visual audits, above-the-fold analysis, competitor page comparison, UX review, or documenting current page state.' This provides clear context for when to use the tool, though it does not explicitly name alternatives or state when not to use it.

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