get_screenshot

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

With no annotations, the description carries the full behavioral burden. It does disclose that no API key is needed and that it returns a PNG image block, which adds useful context. However, it omits details like failure behavior, whether the screenshot is full-page or viewport, and any resource or rate-limit implications, leaving clear gaps.

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 first two sentences are concise and front-loaded. The third sentence is somewhat wordy but provides valuable use-case rationale. Overall, it is not overly long and each sentence contributes meaningful information, though the third could be tightened.

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 one parameter and no output schema, the description covers the key points: what it returns (PNG image block), authentication requirements (none), and intended use case (visual brand-impersonation judgment). Missing details like error conditions and exact scope of the screenshot prevent a perfect score.

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 0%, and the description never explicitly explains the `uuid` parameter beyond the schema's bare property name. While the context implies it identifies the page/scan, the description itself adds no meaning about what value to provide or where to obtain it, failing to compensate for the low schema coverage.

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 begins with a specific verb and resource: 'Fetch the page screenshot as an image you can actually look at.' It clearly distinguishes the tool from siblings like get_dom by emphasizing the visual image output rather than text/DOM data. The screenshot purpose is also explicit.

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 clear context for use: 'so a vision-capable model can judge whether a page impersonates a brand' and 'the thing no field in the JSON captures.' This implies when the tool should be used over other scanning tools, though it does not explicitly mention sibling alternatives or exclusions.

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