browser_take_screenshot

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds a key behavioral trait beyond this: screenshots are not actionable and should be used only for visual inspection. This is valuable context that annotations don't convey, although it doesn't detail other behavioral aspects like return values or file saving behavior.

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 exactly two sentences, with the purpose front-loaded and the crucial usage caveat following immediately. Every sentence earns its place with no wasted words.

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 tool with 6 parameters and no output schema, the description provides enough context for selection: it states the purpose, gives an alternative, and the schema handles parameter semantics. However, it doesn't mention what the tool returns (e.g., an image file path), but the tool name and filename parameter imply this. It is reasonably complete but could be slightly more explicit about the output.

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%, so all 6 parameters are already well-documented in the schema. The description adds no parameter-specific meaning beyond what the schema provides, thus it meets the baseline of 3 without adding extra value.

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 states precisely what the tool does: 'Take a screenshot of the current page.' This is a specific verb + resource, and it clearly distinguishes from sibling tools like browser_snapshot by noting the screenshot cannot be used for actions, making its 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 gives explicit usage 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 (browser_snapshot), fulfilling the when-to-use vs alternatives criterion.

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