capture_page_screenshot

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

With no annotations, the description carries the burden of behavioral disclosure. It adds usefule behavioral facts: the capture is of the visible viewport and will include temporal, scroll, and viewport metadata. However, it does not state the obvious read-only/non-destructive character or describe what the result looks like.

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?

A single sentence with the action front-loaded, the scope stated clearly ('visible browser page viewport'), and the metadata detail appended at the end. No wasted words or repetition.

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 low-complexity tool with one optional parameter and no output schema, this description gives enough to select and invoke it. The only minor gap is that the 'metadata' content is not elaborated, but knowing the exact metadata structure is not needed to call the tool correctly.

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?

The input schema has 100% parameter documentation coverage for the single optional 'format' parameter, so the schema already explains the enum and default. The description adds no extra meaning about the parameter, but does not need to because the schema is complete.

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 opens with the specific verb and resource: 'Capture a screenshot of the visible browser page viewport.' It clearly scopes the operation to the visible viewport as opposed to the full page, and no sibling tool appears to offer screenshot capture, so it is easily distinguished.

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 phrase 'visible browser page viewport' establishes when this tool applies and implies it is not for full-page or off-screen captures. It does not name alternatives or exclusions, but no sibling screenshot tool exists, so explicit routing is less critical.

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