browser_take_screenshot

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

Annotations already convey readOnlyHint=true and destructiveHint=false, so the description adds value by disclosing a behavioral limitation: screenshots cannot be used as a basis for performing actions. This is contextual information beyond the structured annotations, though it does not detail output format or side effects.

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, front-loaded with the primary purpose and immediately followed by a critical usage warning. Every word earns its place; there is no redundancy or extraneous information.

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 tool's moderate complexity (6 parameters, no output schema) and rich annotations, the description covers the core purpose and a key limitation. It does not explicitly state what the screenshot returns or where it is saved, but the schema's filename parameter and the tool's name make this context reasonably implied. The description is sufficiently complete for an agent to select and invoke the tool correctly.

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 input schema provides comprehensive descriptions for all six parameters, including enums and defaults, achieving 100% schema coverage. The tool description adds no additional parameter details, so the baseline score of 3 is appropriate since the schema carries the full 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 clearly states the tool's function: 'Take a screenshot of the current page.' It uses a specific verb and resource, and distinguishes itself from sibling tools by explicitly pointing to browser_snapshot for actions, which prevents confusion.

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 when-not-to-use guidance: 'You can't perform actions based on the screenshot, use browser_snapshot for actions.' This names the alternative tool and clearly delineates when browser_take_screenshot is not appropriate, satisfying the highest bar for usage guidelines.

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