page_screenshot

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

Annotations already declare readOnlyHint=true, openWorldHint=true and destructiveHint=false, so the safety profile is covered. The description adds genuinely new behavior: the screenshot is taken after JavaScript execution, meaning rendered output rather than source, which affects expectations about timing and results. It stops short of noting timeouts, auth-walled pages, or rate limits for this network-dependent capture.

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?

Front-loaded with the core action, followed by a compact use-case list and a short Args block. Every sentence earns its place, and the Args block is not redundant padding given the 0% schema coverage.

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 two-parameter capture tool with annotations covering safety and open-world access, the description covers purpose, rendered-after-JS behavior, and both parameters. The one remaining gap is the return format — image, URL, or binary payload — which is not covered by an output schema either.

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%, so the description has to carry parameter meaning and largely does: url is described as a full URL with an example form, and full_page is explained as full scrollable page versus viewport only, including the default. This is solid compensation for a bare schema, though the URL example could note whether scheme is mandatory or optional.

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 first sentence states a specific verb and resource ('Capture a screenshot of a webpage') and adds that it is a rendered screenshot taken after JavaScript execution, which is a meaningful distinction from a raw-HTML fetch. It does not explicitly name or differentiate against siblings such as on_page_audit or page_speed_audit, leaving that separation to inference from the use-case list.

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 positive context for when to reach for this tool: visual audits, above-the-fold analysis, competitor page comparison, UX review, documenting page state. What is missing is any exclusion or routing guidance — nothing says when to prefer on_page_audit or content_scrape instead.

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