runtime_evaluate

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

No annotations are provided, so the description carries full burden for behavioral disclosure. It only states that code executes in the page context but fails to mention whether execution is synchronous, what side effects are possible (e.g., navigation), error handling, or the effect of the awaitPromise parameter.

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 a parenthetical example. It is front-loaded with the core action and efficiently conveys purpose without unnecessary words.

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—a potentially complex operation—the description lacks completeness. It does not specify return values, error behavior, or side effects, leaving the agent without enough context to use it safely, especially given no output schema.

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% with inline descriptions for both parameters. The tool description adds no additional meaning beyond the schema, meeting the baseline expectation for a tool with complete schema 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 JavaScript code in the page context. It provides concrete usage examples (form filling, login triggering) that help distinguish it from sibling tools like runtime_call_function or runtime_get_global_vars.

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 usage through examples (form filling, login), but does not explicitly state when not to use this tool or suggest alternatives among the many sibling tools. Missing explicit guidance on when to prefer runtime_call_function or other tools.

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