Evaluate JavaScript

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

The description adds value beyond annotations by stating 'bounded' and 'JSON-safe result', and explicitly notes 'This can mutate the page', which aligns with destructiveHint=true and readOnlyHint=false. It provides context on safety and output constraints not covered by 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?

The description is two sentences, front-loaded with the main action, and every word adds value. No redundancy or filler, making it highly efficient for an AI agent.

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?

The description covers the essential behavior: execution, mutability, boundedness, and JSON-safe output. The presence of an output schema further informs return values. Minor missing details like async support do not significantly detract, but completeness is just short of high.

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 the description does not need to add much. The tool description reiterates the function body input but does not enhance understanding beyond the schema. Baseline score of 3 is appropriate.

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 verb 'Run', the resource 'bounded JavaScript function body', and the scope 'in the current page'. It distinguishes from sibling tools by specifying the action of executing custom JavaScript code, which is unique among the listed tools for page interactions.

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 implies usage for custom JavaScript execution but lacks explicit guidance on when to use this tool versus alternatives like page navigation or clicking. No exclusions or prerequisites are mentioned, leaving the agent to infer context.

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