playwright__browser_take_screenshot

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

Annotations already establish read-only and non-destructive behavior, so the description adds value by disclosing the non-interactive nature of screenshots and directing agents to browser_snapshot for actions. This is a meaningful behavioral limitation not captured by the schema or 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?

Two concise sentences with no filler: the first states the core action, and the second delivers a critical usage caveat. The warning is front-loaded enough to be noticed before invocation.

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 six-parameter tool with thorough schema documentation and safety annotations, the description covers the key behavioral distinction from browser_snapshot. The lack of an output schema means return-value behavior is not explicitly described, but the filename parameter and the nature of 'screenshot' make the file-saving outcome reasonably inferable.

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%, and the input schema provides detailed descriptions for all parameters, including enum semantics for 'scale' and the interplay between 'fullPage' and element screenshots. The description adds no additional parameter-level meaning, so the 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 takes a screenshot of the current page with a specific verb and resource, and distinguishes itself from browser_snapshot by noting screenshots cannot drive actions. However, it omits the element screenshot capability exposed by the 'target' and 'element' parameters, so the stated scope is slightly narrower than the tool's actual functionality.

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 warns against using this tool for action-taking and points to browser_snapshot as the alternative, which is clear when-not guidance. It does not explicitly enumerate positive use cases for screenshots, but the purpose is evident from the action described.

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