page_screenshot

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

With no annotations provided, the description carries the full behavioral burden. It usefully discloses side effects and outputs: the screenshot is saved under the session recordings directory, returns the file path, and feeds the live view when enabled. This goes well beyond a bare 'capture screenshot' description, though it could still mention failure modes or prerequisites.

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?

Three short sentences with no filler. The key action is front-loaded, the parameter-dependent mode is stated clearly, and side effects are summarized in the remaining sentences. Every sentence earns its place.

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 description covers the action, output, and side effects reasonably well. However, with no output schema and no annotations, it leaves gaps around required parameters, prerequisite page/session setup, and error conditions, so an agent may not fully understand how to construct a correct invocation beyond the obvious session_id/page_id names.

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 only 33%: full_page is documented in the schema, but the required session_id and page_id have no schema descriptions. The description does not explain what these identifiers refer to beyond the general 'page' and 'session recordings' context, so it fails to compensate for the low coverage gap.

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 and resource: capture a PNG screenshot of a page. It also clarifies the critical scope options (viewport by default, full page with full_page=true) and distinguishes this from sibling tools like page_snapshot by explicitly covering the image-capture behavior.

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 page screenshot is needed, especially a visual record. However, it does not explicitly discuss alternatives such as page_snapshot, nor when screenshot might be inappropriate, leaving selection between siblings partially to inference.

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