evaluate_at_frame

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

Annotations provide only a title, so the description carries the burden. It discloses the pause requirement and the exact scope access, but it omits potential side effects of evaluating arbitrary JavaScript and any error behavior. This is a notable gap for a tool that executes code.

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 three short sentences, each adding unique value: purpose, differentiation, and a critical limitation. No redundancy or fluff; well front-loaded.

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 schema covers parameters and the description explains purpose and constraints, it is largely complete. However, with no output schema and minimal annotations, it does not describe return values or error conditions, leaving some ambiguity for the agent.

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?

Both parameters have schema descriptions, and the description does not add parameter-specific details beyond what the schema provides. The context of frame scope is mentioned, but not tied directly to frameIndex. Schema coverage is 100%, so a baseline of 3 is 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 it evaluates a JavaScript expression in the scope of a paused call frame, and explicitly contrasts with evaluate_js, noting access to local/closure/this. This firmly distinguishes it from sibling tools like evaluate_js and get_scope_variables.

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?

It explicitly names evaluate_js as an alternative and describes the difference, while also stating the prerequisite that execution must be paused. This gives clear when-to-use and when-not-to-use guidance.

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