browser_emulate_media

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

The description only says 'emulates' without clarifying whether the emulation is temporary, persistent, or how it interacts with existing browser state. Although annotations include destructiveHint=true, the description adds no additional behavioral context beyond what the annotations already indicate, so the agent receives minimal extra insight.

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 a single concise sentence with no filler, clearly front-loading the main action. It covers both parameters without unnecessary detail, earning a perfect score for brevity and structure.

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 simplicity, the complete schema, and the presence of annotations, the description is largely sufficient. It could benefit from a note about resetting emulation (e.g., using 'null' or 'no-preference'), but the schema already exposes those enum values, so the description is adequately complete for a straightforward tool.

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 schema provides 100% coverage with descriptions for both parameters, including enums. The description maps directly to these enums (light/dark, screen/print), but does not add significant new meaning beyond what the schema already documents, so a baseline score 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 emulates light/dark color schemes and media type queries (screen vs. print), using a specific verb and resource. This distinguishes it from other browser tools like resize or navigate, and matches the tool name and title.

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 implies usage for testing responsive design or print styles, but does not provide explicit when-to-use or when-not-to-use guidance. There are no alternatives mentioned, so the context is only implicit from the action itself.

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