browser_take_screenshot

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

Annotations already indicate readOnlyHint=true and destructiveHint=false, so the description doesn't need to cover those. It adds valuable behavioral context by explicitly stating that the screenshot cannot be used for actions, which is not derivable from the annotations alone. This is useful for the agent to avoid misuse.

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 sentence that is front-loaded with the core action and immediately provides the key caveat about usage. Every word earns its place, with zero wasted text. It is concise and well-structured.

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 tells what the tool does and a key limitation, but it does not mention what the tool returns (e.g., a file path, image reference) or that it saves a file. With no output schema defined, the agent is left to infer the result, which is a notable gap for a tool that produces a file. The schema covers file naming, but the description doesn't clarify the return value, making it only partially 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?

The schema description coverage is 100%, with all parameters having detailed descriptions (type, scale, target, element, filename, fullPage). The tool description itself adds no additional parameter semantics, but the schema fully covers the parameters, so a baseline of 3 is appropriate.

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 clearly states the tool's action ('Take a screenshot') and the specific resource ('current page'), making it easy to understand its core function. It also distinguishes itself from the sibling tool browser_snapshot by noting that screenshots are not for actions, which differentiates it from a very similar-sounding tool.

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 explicitly states when NOT to use this tool: 'You can't perform actions based on the screenshot' and provides the alternative 'use browser_snapshot for actions.' This gives clear, actionable usage guidance and differentiates from a key sibling tool.

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