browser_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 covered. The description adds a behavioral limitation ('You can't perform actions based on the screenshot') and mentions saving to a file via filename, which goes beyond the annotation. This extra context about tool behavior is valuable, though the core safety profile is already in the annotations.

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 concise and well-structured. It leads with the core purpose in the first sentence, then immediately provides a critical usage warning (not for actions) in the second sentence. No unnecessary words or redundant information. It is frontal and easy to parse.

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, combined with the schema, provides enough context for an agent to correctly invoke the tool. It covers the action, the limitation (no actions), and the key parameter behaviors (fullPage, element). It does not describe the return value, but since there is no output schema and it is a standard screenshot tool, this omission is not critical. Slightly missing explicit mention that the screenshot is saved or returned, but overall sufficient.

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%, as every parameter has a description. The tool description itself does not add much beyond the schema—it only mentions the current page. Since the schema already fully explains parameters, the description adds no new semantic value, but it does not detract either. Baseline score 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 primary action: 'Take a screenshot of the current page.' It specifies the resource (the current page) and the verb (take a screenshot), and distinguishes it from the sibling browser_snapshot tool by noting that screenshots are not for performing actions. This makes the purpose unambiguous.

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 provides usage guidance by stating 'You can't perform actions based on the screenshot, use browser_snapshot for actions.' This tells the agent when not to use this tool and points to the alternative. Additionally, the parameter descriptions (e.g., fullPage, element) explain when to use different options, providing comprehensive context for tool selection.

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