set_device

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

Discloses that cookies and localStorage are preserved, returns page_state, and cannot be used with sub-agents. No annotations provided, so description carries full burden; it does not 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?

Four sentences, front-loaded with main action, each sentence provides useful information without redundancy.

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?

Covers return value (page_state) and usage constraint (sub-agents). Lacks details about what happens if device is set while custom params are present, but schema already enforces exclusivity.

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 baseline is 3. The description adds context about using presets vs custom fields but does not significantly enhance understanding beyond the schema.

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?

Clearly states the tool switches browser device emulation between mobile and desktop modes, specifying it recreates the browser context with viewport, user agent, and touch settings. Distinct from any sibling tool.

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?

Provides guidance on using preset device names versus custom parameters, and explicitly states it cannot be used while sub-agents are running. However, no explicit alternative tool comparison is needed as no sibling does emulation.

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