emulate_user_agent

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 the action ('override') but does not mention persistence, reversibility, interaction with other emulation settings, or side effects. This is insufficient for an agent to understand the tool's runtime behavior.

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, direct sentence with no unnecessary words, making it very concise. However, it is extremely brief and could have included additional useful context without becoming verbose, so it does not earn a perfect 5.

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 large set of sibling emulation tools and the absence of annotations, the description is too minimal to provide complete context. It does not explain how this tool fits into the emulation workflow, whether it can be reset, or what to do if multiple emulations are active. Without output schema, it also omits return value expectations.

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% description coverage for all three parameters (platform, userAgent, acceptLanguage), so the schema already explains each parameter. The tool description adds no extra parameter-level information beyond what the schema provides, hence the baseline score 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 'Override the browser's user agent string' uses a specific verb ('override') and a clear resource ('browser's user agent string'), making it distinct from sibling tools like emulate_device or emulate_locale. It unambiguously states what the tool does.

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?

There is no guidance on when to use this tool versus alternatives such as emulate_device, which may also affect the user agent. The description provides no context, prerequisites, or exclusions, leaving the agent without direction on selecting this tool.

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