browser_execute_js

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

The description only repeats the basic purpose. It does not disclose side effects (DOM changes, navigation, network requests), return value behavior, async handling, or potential dangers. With no annotations, this is a critical omission for a powerful tool.

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 with zero waste. It is as concise as possible and front-loads the core action. No unnecessary words or repetition.

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?

Although the tool has only one parameter and no output schema, executing JavaScript on a page can produce side effects and returns a value. The description does not cover expected outcome, return format, or side effects, making it 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?

Schema coverage is 100% for the single parameter 'script', which is described as 'JavaScript code'. The description adds no extra meaning beyond the schema, but the baseline of 3 is appropriate since the schema already provides full parameter documentation.

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 'Execute' and the resource 'JavaScript on the page', giving a specific action with scope. This distinguishes it from all sibling tools, which are for navigation, clicking, typing, etc., and none other execute arbitrary JS.

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 use cases, prerequisites, or exclusions, leaving the agent without explicit direction on when to invoke it.

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