execute_js

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 that arbitrary JS is executed, without mentioning potential side effects, page state changes, permission requirements, or what happens on errors. This is a significant gap for a tool that runs arbitrary code, which could alter the page or cause navigation.

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, concise sentence with no unnecessary words or repetition. It effectively communicates the core action in the most efficient way possible, earning top marks for conciseness.

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?

Despite having only one parameter, the tool's complexity demands more context. The description does not explain what the tool returns (e.g., the script's result), how it handles async operations, or any risks associated with arbitrary code execution. This makes the description incomplete for safe and correct use.

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 fully covers the only parameter 'script' with the description 'The JS code to execute'. The tool description adds no further semantic meaning beyond inferring that the script is JavaScript, so the baseline score of 3 is appropriate because the schema already handles the parameter.

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 'Execute arbitrary JavaScript in the browser context' uses a specific verb ('execute') and resource ('JavaScript in the browser context'), making the purpose immediately clear. It distinctly separates this tool from siblings like navigate, capture_screenshot, and get_console_logs, which all have different functions.

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?

No guidance is provided on when to use this tool versus alternatives. The description does not mention any prerequisites, exclusions, or scenarios where other tools (e.g., interact, inspect_element) might be more appropriate, leaving the agent without clear decision-making support.

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