eval

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

There are no safety or behavior annotations beyond a title, so the description carries the full burden of disclosing side effects. It does not mention that executing arbitrary JavaScript can modify page state, trigger navigation, or cause side effects, nor does it describe how the result is serialized or returned. The async/Promise support is helpful but minimal behavioral context.

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, efficient sentence that front-loads the core action and outcome. It is not bloated and is easy to parse, though it omits some behavioral context that would make it more useful.

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 lack of an output schema and behavioral annotations, the description is not complete enough. It does not explain the result format, error behavior, page-load semantics, or how this differs from session_eval. The optional 'wait_secs' behavior is also not clarified beyond its schema definition.

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 schema description coverage is 100%, so the parameters are already documented in the input schema. The description does not add meaningful detail about 'url', 'script', or 'wait_secs' beyond what the schema provides, making the baseline score of 3 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 action ('Execute JavaScript'), the target ('on a webpage'), and the expected outcome ('return the result'). It is not a tautology and adds the async/Promise capability. However, it does not distinguish itself from the sibling session_eval, which likely performs a similar action within an active browser session.

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 no guidance on when to use this tool instead of alternatives such as session_eval. The required 'url' parameter implies it may load a page before executing, but this behavior is not stated, leaving the agent to infer the tool's role in the workflow.

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