set_user_agent

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

With no annotations, the description must disclose behavioral traits. It indicates mutation ('override') but does not explain side effects, reversibility, auth requirements, or the implications of 'BiDi emulation.' The agent is left uninformed about the tool's impact.

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, which is concise. However, the redundant 'setUserAgentOverride.' at the end wastes space and could be removed. Front-loading is adequate.

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 no output schema, moderate parameter count (2), and lack of annotations, the description is insufficient. It does not explain the return value, error conditions, or how the contextId parameter works. A complete description should include these details.

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 description coverage is 0%, so the description must add meaning to the parameters. It provides no information about 'userAgent' or 'contextId,' leaving the agent to infer from names alone. This is a significant gap.

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 states the specific action: overriding the User-Agent string for a browsing context. It is clear and distinguishes the tool from siblings like set_javascript_enabled or set_csp_enabled. However, the trailing 'setUserAgentOverride.' is redundant and slightly confusing.

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 (e.g., other emulation or override tools). No context about prerequisites, such as needing an active browsing context.

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