screenshot

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

Discloses return type (binary image data), credit cost (5 credits per request), and notes that no country/proxy/session parameters are documented. It also mentions the wait_until parameter controls load timing. This adds value beyond the schema and annotations (which are absent).

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 front-loaded with the main action but includes extraneous details about documentation structure (e.g., 'only one of the fetched pages that ships a full, structured API Parameters reference table') that may not aid an AI agent. Could be more concise.

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?

Given 7 parameters, no output schema, and no annotations, the description adequately covers purpose, parameters, output type, and credit cost. It lacks error handling details but sufficiently describes the return format for a screenshot tool.

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 description coverage is 100%, so baseline is 3. The description adds credit cost and documentation notes but does not add significant new meaning beyond what the schema already provides for each parameter.

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 starts with 'Captures a screenshot of any webpage' which clearly states the action (captures) and resource (screenshot of webpage). It lists controllable aspects and distinguishes from the sibling 'scrape' by noting it's a distinct endpoint, providing clear differentiation.

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 gives context by contrasting with /scrape endpoint, implying this tool is for image capture rather than HTML scraping. However, it does not explicitly state when to use this tool over other siblings or provide when-not conditions.

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