js_execute

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

Describes execution context (function body, args via arguments object), serialization behavior (primitives, DOM elements, non-serializable values), and failure condition (alert dialog open). Lacks mention of side effects on page state, but overall transparent.

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?

Concise, front-loaded, and no extraneous information. Each sentence adds value in a compact format.

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?

Covers main aspects: action, execution model, return value, and when to use alternatives. Output schema exists, so return details are covered. Could be more explicit about tab_id parameter, but overall complete for the complexity.

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?

With 0% schema description coverage, the description should compensate but only mentions how to access args (arguments[0], etc.) without explaining the 'code' parameter format or the purpose of 'tab_id'. Leaves significant gaps for agent understanding.

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?

Clearly states 'Execute JavaScript code on the current page and return the result.' Differentiates from siblings by positioning as an escape hatch for unsupported operations, referencing specific alternatives like element_click and page_navigate.

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?

Explicitly advises to use specific tools when available and to use this only as an escape hatch for unsupported operations, providing clear when-to-use and when-not-to-use guidance.

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