take_screenshot

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

Annotations already declare readOnlyHint=true, so the read-only nature is known. The description adds that the tool supports configurable viewport size, full-page mode, and image quality, which are behavioral options. However, it does not disclose potential failure modes (e.g., inaccessible pages), loading behavior, or any rate limits. Given the annotations cover the safety profile, a score of 3 reflects the modest extra value.

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 a single, tight sentence that leads with the primary action and format, then lists the key configurable aspects. There is zero redundancy or filler, and all content is relevant to an agent deciding whether to invoke the tool. It is appropriately front-loaded with the core purpose.

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?

The tool has 6 parameters and no output schema, so the description should ideally indicate what the tool returns (e.g., an image) and any operational caveats (e.g., waits for page load, size limits). While the purpose clearly implies an image output, it is not explicitly stated, and no limitations or error scenarios are mentioned. For a fairly simple tool this is acceptable but not fully complete.

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%, with every parameter (url, width, format, height, quality, full_page) already having descriptive text. The description's mention of 'Configurable viewport size, full-page mode, and image quality' merely restates what the schema already documents, adding no new semantic insight. Baseline of 3 is appropriate since the schema does the heavy lifting.

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 states a specific verb ('Capture') and a clear resource ('a screenshot of any webpage'), and mentions the output formats (PNG/JPEG). This is distinct from all sibling tools, none of which perform screenshot capture, so it fully differentiates the tool's purpose.

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 when to use the tool (whenever a webpage screenshot is needed) but provides no explicit guidance on alternatives or exclusions. It does not mention that tools like html_to_pdf might serve a related but distinct purpose, nor does it state any limitations on usage. Usage context is clear but not explicitly contrasted with alternatives.

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