screenshot

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

Discloses cost ($0.015/call) and wallet requirement, and notes the use of headless Chromium. However, lacks details on failure modes (e.g., loading errors, timeouts) or rate limits, which are important for a paid tool.

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?

Extremely concise: cost tag, purpose, result type, and parameter summary in a single sentence with no 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?

For a simple tool with two parameters and no output schema, the description adequately covers cost, usage constraints (public URL), and result type (PNG). Could mention error handling or default behavior for fullPage=false, but sufficient.

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 coverage is 100%, and the description repeats the parameter usage ('Query params: ?url=…&fullPage=true'). No additional semantic meaning beyond schema is provided.

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 'Screenshot any public URL' using headless Chromium, specifying the action, target, and implementation. It contrasts with sibling tools like 'pdf' and 'render' by emphasizing PNG output.

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?

No guidance on when not to use this tool or alternatives among siblings. Only mentions 'any public URL' as a constraint, but does not explain when to prefer it over 'pdf' or 'render'.

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