Evaluate JavaScript

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

Annotations already disclose destructiveHint=true and readOnlyHint=false. The description adds 'This can mutate the page,' reinforcing the destructive nature, and 'bounded,' which hints at execution limits but does not specify them. No contradiction with 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 core action and result, and contains no filler. It efficiently communicates the essential information.

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?

For a tool that executes arbitrary JavaScript, the description covers the main action and output format, but lacks important context such as error behavior, timeout specifics, or broader side-effect implications beyond mutation. An output schema exists, but given the high-risk nature, more context would be beneficial.

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%, with each parameter well-documented in the schema (script as a function body, args as JSON arguments, max_chars as a limit). The description itself adds no additional parameter details, so the schema carries the full semantic weight.

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 tool's action: running a bounded JavaScript function body in the current page and returning a JSON-safe result. This distinguishes it from all sibling tools, as no other tool offers JavaScript execution.

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 the tool is used to run JavaScript on the page, but provides no explicit guidance on when to choose it over dedicated interaction tools or when not to use it. There is no mention of alternatives or exclusions.

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