Evaluate JavaScript in Page

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

The description mentions executing JavaScript in the page, implying side effects, but does not elaborate on potential risks (e.g., page modifications, error handling, async behavior). With 'openWorldHint: true' in annotations, the description adds modest context but could be more forthcoming about behavioral traits.

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 concise and well-structured: a one-line summary followed by bulleted use cases and clear parameter explanations. Every sentence adds value 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?

Given the complexity of executing arbitrary JavaScript, the description covers the main functionality, argument usage, and return value. It does not discuss error handling or security implications, but the presence of an output schema (not shown) reduces the need for return value details. Slightly more completeness would be ideal.

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?

Despite 0% schema description coverage, the description adds critical meaning: 'script' is defined as a 'JS expression or arrow function' and 'arg' as an 'Optional argument to pass to a function script.' This fully compensates for the lack of schema descriptions.

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 'Run JavaScript in the active page and return the result' with specific, concrete use cases (e.g., extracting CSRF tokens, reading localStorage). This uniquely identifies the tool and distinguishes it from sibling tools like gv_get_page_content or gv_fill_input.

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 explicit use cases and examples, guiding when to use the tool (e.g., extracting values, calling site functions). However, it does not explicitly state when not to use it or offer alternatives, which would improve clarity for the agent.

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