ruyi_emulate_useragent

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

With no annotations, the description carries the full burden of behavioral disclosure. It notes that the tool overrides navigator.userAgent, but does not explain scope (e.g., per-page vs global), persistence across navigations, or how to reset the user agent. This leaves significant behavioral ambiguity.

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 extremely concise, with two short clauses that deliver the core purpose without any wasted words or repetitive information.

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?

Despite having two parameters and no output schema, the description is minimal. It does not explain the effect scope (curent page or all pages), relationship to pageIdx, or how the emulation interacts with browser navigation or other tools. This is insufficient for an agent to use it confidently.

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 50% (only userAgent is described, pageIdx is not). The description does not mention parameters at all, so it adds no meaning beyond the schema. The meaning of pageIdx (likely page index) is left unclear.

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 simulates a browser UserAgent string and specifically overrides navigator.userAgent. This is a specific verb+resource that distinguishes it from sibling emulation tools like ruyi_emulate_geolocation, ruyi_emulate_timezone, and ruyi_emulate_locale.

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 provides no guidance on when to use this tool versus alternatives, nor does it mention exclusions or prerequisites. The sibling tools include other emulation functions, but the description doesn't differentiate usage scenarios.

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