browser_screenshot

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It mentions capturing the 'visible page area' which adds some context about scope, but fails to address critical aspects like whether this requires specific permissions, if it's a blocking operation, what happens on failure, or what the output format is (e.g., base64 string, file path).

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, efficient sentence that directly states the tool's function without unnecessary words. It's appropriately sized and front-loaded, making it easy to understand at a glance.

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?

Given the complexity of a screenshot tool with 2 parameters, no annotations, and no output schema, the description is insufficient. It lacks information about return values, error conditions, dependencies (e.g., requires an open browser page), and behavioral details. The description alone doesn't provide enough context for reliable use.

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 50% (only 'quality' has a description), and the description adds no parameter information beyond what's in the schema. It doesn't explain what 'format' controls or provide context for 'quality' values. Since schema coverage is moderate, the baseline is 3, but the description doesn't compensate for the gaps.

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 action ('capture') and resource ('screenshot of the visible page area'), making the purpose immediately understandable. However, it doesn't explicitly differentiate from sibling tools like 'browser_snapshot' which might have overlapping functionality, preventing a perfect score.

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?

No guidance is provided on when to use this tool versus alternatives like 'browser_snapshot' or other browser tools. The description only states what it does, not when it's appropriate or what prerequisites might be needed (e.g., requiring an active browser page).

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