browser_take_screenshot

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

While annotations already declare readOnlyHint=true and destructiveHint=false, the description adds a unique behavioral trait: the screenshot cannot be used as a basis for actions. This goes beyond the safety profile, clarifying the utility of the output. It doesn't contradict any 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 sentences with zero fluff. The primary action is front-loaded, and the crucial caveat about not using the screenshot for actions is placed second. Every word earns its place; nothing is redundant.

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 a rich, fully-documented schema, the description covers all essential context: what it does, when not to use it, and a key limitation. No output schema exists, so return values need not be explained. The description is complete for an agent to call it correctly without further guidance.

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 100% coverage with detailed descriptions for all six parameters (type, scale, target, element, filename, fullPage). The tool description adds no parameter-specific meaning beyond the schema, so based on the high schema coverage, 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 states a specific action ('Take a screenshot of the current page') on a clear resource, and explicitly differentiates it from browser_snapshot by noting the latter is for actions. This unambiguously distinguishes the tool from its siblings without needing the schema.

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?

It provides an explicit exclusion: 'You can't perform actions based on the screenshot, use browser_snapshot for actions.' This names the alternative (browser_snapshot) and the condition under which to use it (when actions are needed), fulfilling the criterion of explicit when-to-use vs alternatives.

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