emulate_device

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It only states what is emulated (viewport, DPR, user agent, touch) but does not explain whether the emulation overrides existing settings, persists across sessions, or can be reverted. The presence of sibling tools like emulate_clear_all suggests important behavioral context that is missing.

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 sentence, front-loaded with the main action, and contains no unnecessary words. It efficiently conveys the tool's scope and effect.

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?

The tool is simple with only one parameter and no output schema, so the description covers its core purpose well. However, it lacks important behavioral context about how the emulation interacts with other emulation settings, whether it clears prior configuration, and how it can be reverted. Given the absence of annotations, this is a notable gap.

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 has 100% coverage with an enum and a minimal description ('Device preset to emulate'). The tool description adds meaning by explaining that choosing a device will apply correct viewport, DPR, user agent, and touch, which is beyond what the schema provides. This extra context justifies a score above the baseline of 3.

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 purpose with a specific verb ('Emulate') and resource ('specific device'), and enumerates the concrete aspects it configures (viewport, DPR, user agent, touch). This distinguishes it from sibling tools that target individual emulation aspects, such as emulate_user_agent or emulate_custom_device.

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 by listing the comprehensive set of device properties, which suggests it is the preferred tool for full-device emulation as opposed to single-property emulators. However, it does not explicitly state when to use this tool versus alternatives, nor does it provide any exclusions or conditions.

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