browser_take_screenshot

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

Annotations (readOnlyHint: true, destructiveHint: false) already establish the safety profile. The description adds a non-obvious behavioral constraint: screenshots cannot be used as a basis for actions. This is valuable context beyond the annotations. No contradictions exist.

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 two sentences with zero waste. It front-loads the core purpose and then provides a critical usage distinction. Every word 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?

For a relatively simple screenshot tool with excellent schema coverage, the description is functionally complete. It covers the main caveat (actions require browser_snapshot) and the schema handles all parameter details. No output schema exists, but the return type (screenshot image) is self-evident from the tool's name and purpose.

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%, with detailed descriptions for all six parameters (type, scale, target, element, filename, fullPage). The description itself adds no additional parameter context, so the baseline score of 3 is appropriate given that the schema carries the semantic burden.

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 uses a specific verb and resource: 'Take a screenshot of the current page.' It clearly distinguishes the tool from browser_snapshot by noting that screenshots cannot be used for actions, which is a key differentiating detail.

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 provides explicit guidance: 'You can't perform actions based on the screenshot, use browser_snapshot for actions.' This directly tells the agent when not to use this tool and names the alternative, making the usage context unambiguous.

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